Holo Theme Is Now Mandatory For Android Devices
tripleevenfall writes in about the new theme changes in Android 4.0. From the article: "Starting with Android 4.0, support for the 'Holo' theme will be mandatory for phones and tablets that have the Android Market installed. Holo is the stock Android theme, known for its sharp angles, thin lines and blue hue. Third-party developers can now create apps and widgets using the default Android aesthetic, knowing that's how it'll look on every major Ice Cream Sandwich device that has the Android Market. "
This is not banning custom themes; instead it is merely giving developers a consistent theme that is guaranteed to be installed if they want a consistent look across all devices. There are even a few improvements to the style protocol to help developers deal with dark and light themes.
It's depressing when my mom asks me to do something on her new Verizon Android phone and I stare at it in confusion for more than 5 minutes. I've owned a Nexus One since they were sold though so I guess it's my fault in thinking the phone companies wouldn't slather their layer of ugly paint on everything.
Android is nice because it allows the companies selling/branding the phones to do it their way.
Unfortunately they are better at stealing money then they are designing UIs.