Singing my favorite tune once again:

I want a cross-platform story for managed code.  Any story.  I envy my Java brethren because although "Write Once Run Everywhere" is a big over-promise, it actually is possible to write a Java program which runs on multiple platforms.

Don't feel like you have to aim high.  Feel free to make .NET's cross-platform support as lame as Java's client-side GUI support.

I like C#.  More importantly, I just turned 35 so I am way too old to ever learn another programming language.  Please make C# awesome.  It is probably the last language I will ever use.