Yes, you can go "closed source" after you've licensed something under the GPL if you are the sole author, or can get the written permission to do so from all of the authors and contributors. As the author (or authors) of a work, you are free to release it under multiple licenses, or change your license in subsequent versions.
What you can't do is "take back" versions that have already been released under the GPL. You can't stop people who are using the GPL'ed version from continuing to use and update that code - even if you release the code under a different license.
As a practical example, say I write something called InFooSec 0.1 and release it under the GPL. As it turns out, nobody is interested in contributing, so I get only a handful of changes from the Free Software community - most of which I decline to implement in the codebase. I sell some support and consulting on InFooSec, and generally manage to scrape by, making improvements and adding features with an eye towards a vastly improved 0.2 release.
For whatever reason (perhaps I have a competitor who is a really gifted salesperson and sells InFooSec pre-installed on some hardware at a huge profit), I decide that InFooSec 0.2 will be closed source software. Now, InFooSec 0.2 is a derivative work of version 0.1, so I need some right to use InFooSec 0.1... and since 0.2 will be closed source, the GPL doesn't provide me with that right. However, as the author of InFooSec 0.1, I already own all of the rights to the code. I can do anything I wish to do with my own code - I don't need a license from the GPL to do it. So it's perfectly legal for me to release 0.2 under any license I choose.
If I'm not personally the author of all of 0.1 (or if I'm not personally the author of all of the improvements in 0.2), then I have to buy the rights or otherwise get a license from the original authors to use their portions in InFooSec 0.2. Any code that I can't get permission to use under my non-GPL license will have to be left out, or rewritten. For a small number of additional authors, or for non-critical features, this is probably quite practical.
SO I can release InFooSec 0.2 under my new, closed-source license. It has a bunch of nifty new features that should make it very competitive in the marketplace. My main competitor is still using the "old" version 0.1, and can continue to do so indefinitely under the GPL. Hopefully the new features in 0.2 will let me clobber them from a technical standpoint. Of course it's no guarantee - because 0.1 was GPL'ed, my competitor can hire a hot-shot programmer to improve InFooSec 0.1, thus forking the project.
You are probably right to say that Linux could never be released under a different license. The sheer number of authors involved makes this practically impossible. I can't imagine getting them all to agree on new license terms. Even managing to contact every single one of them could be problematic.
I have one in my hand now, and your fears are absolutely unfounded. I basically just plugged the new mouse in in place of my Kensington 2-button+scroll-wheel mouse. I have had no problems using it, and haven't had to teach myself new mousing habits. All in all, my initial impression is very positive: Apple has thought out the ergonomics of this thing, and it does work as advertised.
The Mighty Mouse has good tactile feedback - the actual button-click mechanism is exactly like the 1-button Pro mouse. When you click it, you can feel the mechanism clicking. Like the Pro mouse, you can rest your fingers on either side of the scroll ball without triggering a click.
Only when the mouse is mechanically "clicked" does it look at the pressure sensor to figure out if you're pushing on the left or right side. Even then, it senses pressure rather than just touch, so you can reliably make a left-click or right-click even while your other finger is still resting on the other "button". The scroll-ball "button" works the same way, and also registers reliably.
The scroll ball itself is excellent - it spins freely, and has a small mechanical detent as well as an audible click. I think the scroll click is generated by a small speaker in the mouse, and it sounds exactly like the iPod's scroll wheel sound.
The side buttons took the most getting used to - mainly because I keep forgetting that they exist and don't use them. Triggering the side buttons takes a surprising amount of thumb pressure, so accidental clicks are not a problem here, either.
Picking up the mouse and moving it around doesn't cause a side-click, either. There seems to be some type of lock-out logic; it takes a lot more force to trigger the side buttons when the mouse is in the air, so accidental clicks aren't a problem unless you're really trying to crush the mouse in your hand.
Show me one Mac owner that doesn't log on using an administrator class account (default, no password, auto logon).
Me.
And I recommend it to anyone else running Panther, too.
I do my work as an ordinary user, without auto-login and with a password. I have an administrator account that I use for software installs and system work. It also has a password (and no auto-login).
Running as an ordinary user has saved me from loosing data to a few stupid mistakes (and one buggy program I was working on). I find there isn't anything that I need to do as an user of the system that I can't do from the "ordinary" user account. When I do need to switch to the system user (for example, to install software or fiddle with settings), it's very easy to move between the two accounts when I need to, with Fast User Switching.
Then again, I am an old-school UNIX sysadmin, and I tend to run my Mac as if it was a BSD-based workstation...
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Yes, you can go "closed source" after you've licensed something under the GPL if you are the sole author, or can get the written permission to do so from all of the authors and contributors. As the author (or authors) of a work, you are free to release it under multiple licenses, or change your license in subsequent versions.
... and since 0.2 will be closed source, the GPL doesn't provide me with that right. However, as the author of InFooSec 0.1, I already own all of the rights to the code. I can do anything I wish to do with my own code - I don't need a license from the GPL to do it. So it's perfectly legal for me to release 0.2 under any license I choose.
What you can't do is "take back" versions that have already been released under the GPL. You can't stop people who are using the GPL'ed version from continuing to use and update that code - even if you release the code under a different license.
As a practical example, say I write something called InFooSec 0.1 and release it under the GPL. As it turns out, nobody is interested in contributing, so I get only a handful of changes from the Free Software community - most of which I decline to implement in the codebase. I sell some support and consulting on InFooSec, and generally manage to scrape by, making improvements and adding features with an eye towards a vastly improved 0.2 release.
For whatever reason (perhaps I have a competitor who is a really gifted salesperson and sells InFooSec pre-installed on some hardware at a huge profit), I decide that InFooSec 0.2 will be closed source software. Now, InFooSec 0.2 is a derivative work of version 0.1, so I need some right to use InFooSec 0.1
If I'm not personally the author of all of 0.1 (or if I'm not personally the author of all of the improvements in 0.2), then I have to buy the rights or otherwise get a license from the original authors to use their portions in InFooSec 0.2. Any code that I can't get permission to use under my non-GPL license will have to be left out, or rewritten. For a small number of additional authors, or for non-critical features, this is probably quite practical.
SO I can release InFooSec 0.2 under my new, closed-source license. It has a bunch of nifty new features that should make it very competitive in the marketplace. My main competitor is still using the "old" version 0.1, and can continue to do so indefinitely under the GPL. Hopefully the new features in 0.2 will let me clobber them from a technical standpoint. Of course it's no guarantee - because 0.1 was GPL'ed, my competitor can hire a hot-shot programmer to improve InFooSec 0.1, thus forking the project.
You are probably right to say that Linux could never be released under a different license. The sheer number of authors involved makes this practically impossible. I can't imagine getting them all to agree on new license terms. Even managing to contact every single one of them could be problematic.
I have one in my hand now, and your fears are absolutely unfounded. I basically just plugged the new mouse in in place of my Kensington 2-button+scroll-wheel mouse. I have had no problems using it, and haven't had to teach myself new mousing habits. All in all, my initial impression is very positive: Apple has thought out the ergonomics of this thing, and it does work as advertised.
The Mighty Mouse has good tactile feedback - the actual button-click mechanism is exactly like the 1-button Pro mouse. When you click it, you can feel the mechanism clicking. Like the Pro mouse, you can rest your fingers on either side of the scroll ball without triggering a click.
Only when the mouse is mechanically "clicked" does it look at the pressure sensor to figure out if you're pushing on the left or right side. Even then, it senses pressure rather than just touch, so you can reliably make a left-click or right-click even while your other finger is still resting on the other "button". The scroll-ball "button" works the same way, and also registers reliably.
The scroll ball itself is excellent - it spins freely, and has a small mechanical detent as well as an audible click. I think the scroll click is generated by a small speaker in the mouse, and it sounds exactly like the iPod's scroll wheel sound.
The side buttons took the most getting used to - mainly because I keep forgetting that they exist and don't use them. Triggering the side buttons takes a surprising amount of thumb pressure, so accidental clicks are not a problem here, either.
Picking up the mouse and moving it around doesn't cause a side-click, either. There seems to be some type of lock-out logic; it takes a lot more force to trigger the side buttons when the mouse is in the air, so accidental clicks aren't a problem unless you're really trying to crush the mouse in your hand.
Show me one Mac owner that doesn't log on using an administrator class account (default, no password, auto logon).
Me.
...
And I recommend it to anyone else running Panther, too.
I do my work as an ordinary user, without auto-login and with a password. I have an administrator account that I use for software installs and system work. It also has a password (and no auto-login).
Running as an ordinary user has saved me from loosing data to a few stupid mistakes (and one buggy program I was working on). I find there isn't anything that I need to do as an user of the system that I can't do from the "ordinary" user account. When I do need to switch to the system user (for example, to install software or fiddle with settings), it's very easy to move between the two accounts when I need to, with Fast User Switching.
Then again, I am an old-school UNIX sysadmin, and I tend to run my Mac as if it was a BSD-based workstation