Personally, I think the Netduino is awesome. I love C# and I think that Visual Sutio 2010 is the best programming environment available. I like that it's 32 bit and beefed up a bit and is compatible with existing arduino shields. Plus, being able to program it in C# is a huge plus.
As soon as I heard about it, I ordered one and loaded up the development tools. I've already ported my code from C to C# and am ready to testit out once the thing arrives.
I think the release of this is one of the great things about an open platform. SOmeone can take it in a new direction. IF you aren't interested in this new direction, stick with Wiring and the Arduino environment, if you like C# and want to go that route, go ahead.
THanks Secret Labs.