Now that the G1 with Google's Android OS is now available (soon), will the android platform ever support .Net?
Update: Since I wrote this answer two years ago, we productized Mono to run on Android. The work included a few steps: porting Mono to Android, integrating it with Visual Studio, building plugins for MonoDevelop on Mac and Windows and exposing the Java Android APIs to .NET languages. This is now available at http://monodroid.net
Mono on Android is based on the Mono 2.10 runtime, and defaults to 4.0 profile with the C# 4.0 compiler and uses Mono's new SGen garbage collection engine, as well as our new distributed garbage collection system that performs GC across Java and Mono.
The links below reflect Mono on Android as of January of 2009, I have kept them for historical context
Mono now works on Android thanks to the work of Koushik Dutta and Marc Crichton.
You can see a video of it running here: http://www.koushikdutta.com/2009/01/mono-on-android-with-gratuitous-shaky.html
And you can get the instructions to build Mono yourself here: http://www.koushikdutta.com/2009/01/building-mono-for-android.html
You can get a benchmark comparing Mono's JIT vs Dalvik's interpreter here: http://www.koushikdutta.com/2009/01/dalvik-vs-mono.html
And of course, you can get a pre-configured image with Mono here (go to the bottom of the post for details on using that): http://www.koushikdutta.com/2009/01/building-mono-for-android.html