Is Visual Studio 2008 supported?
James WebsterUnfortunately the VS schedule and the MF 2.5 schedule did not allow us to align, as such 2.x requires VS 2005. Support for 2008 is on the current schedule for our next release (no dates announced yet... stay tuned).
Is Visual C# Express enough?
No. You need Standard Edition and up.
Is only C# language supported?
Officially, only C# is supported. However, you can use the MetaDataProcessor.exe included in the SDK's Tools directory to convert any .NET assembly into the stripped PE file deployable to the device. In fact, Christopher Fairbairn showed how to compile VB.NET code and run it on the device emulator on his blog.