From day one Microsoft has had a central focus on software development, and in programming especially.
With the XBox 360 release quickly approaching, I noticed one important oversight in the XBox 360 platform...
If you look back to the Atari 2600, one of the cartridges Atari released was Basic Programming. This allowed the end user to create their own applications and games for the Atari 2600, albeit very limited ones.
Microsoft has released dozens of programming languages for almost as many platforms, everything from desktops, pda's, tablet pc's, smartphones, and even watches.
I think there is a huge untapped pool of possibilities for end user created content.
Maybe something like a .NET Compact Framework for XBox 360. It seems like an absolute winner to me. I'd think Microsoft could port Windows CE to XBox 360 even if it required an emulator to run. I also think it is a move in and of itself that could push XBox 360 to the lead in the console wars.
Now the question is how to make it happen...