I think a translation from Arduino to NETduino would be a great thing to have
.NET supports C++ as language so porting code from Arduino to NETduino is not 100% difficult. You need to define the main as it is defined in Arduino core
and a part of the code will compile. More work will be the hardware IO, registers, in theory one only need to rewrite the HW abstraction layer once to be able to compile the libraries. But then still one would have a single thread .exe and miss the added value/posibilities of multithreading of the .NET platform. Still the result could be good enough for many sketches.
Personally I believe more in reuse at design and architecture level than at code level. The current trend of Model Driven Design which replaces coding more and more is a very powerfull one. See for example - http://www.verum.com/
- I don't expect it comes to Arduino soon, but I like to be proven wrong on this one