The State of WiiWare, Xbox Alternatives
CVG is running a piece discussing the current state of WiiWare, and where they expect it to go in the future. They point to the success of Mega Man 9 on WiiWare and other platforms, but worry that the perception will arise that certain games are "too good" to be featured on WiiWare. GameSetWatch has a related interview with independent developer Ninjabee discussing their recent games and comparing WiiWare with Xbox Live Arcade. Meanwhile, Microsoft has announced that the new Xbox Experience coming in November will included their Community Games initiative, which will allow amateur game developers to create and share games using the XNA development tools.
I bet they will allow it but be prepared for a hassle. I mean look at the friend code system they have for playing games with your friends.
The best bet to see how Nintendo will do this is to find the instructions they have right now for transferring your account from a dead Wii to a replacement unit. That will give you a general idea of how some future transfer of accounts will work.
Also this is the same company that wanted me to pay $5 for Super Mario Brothers (AGAIN). Nintendo should have made this a free download when the Wii launched. So expect anything from them.