As a long time .NET lover, it's good to see it being pushed in the direction of gaming. I think it will be many, many years before we see any major third party game entirely written on he .NET framework but I hope we get there someday. XNA is really cool for that reason, and it's great to see game development be more accessible than ever. It's like when video cameras became available to kids to make little stories and stuff, and those kids are now directing the stylish movies you see every day. XNA is another example of a new creative outlet for a medium to grow upon.
But I haven't done much with XNA except install it. One reason I haven't done much is because there's no content pipeline. It can't load .X files. So a bunch of people out on the web are writing their own importers as a result. Hopefully someone will code up a Collada reader before I really get into using XNA so I don't have to write it myself.
Oh, and if you're in the market for an interchange format, might I recommend Collada? I've been working with various companies and individuals to smooth out some of the kinks in this format and it's coming along very nicely. I'm kind of surprised that Microsoft is going to support FBX in their default content pipeline over Collada. I know Collada is originally Sony's thing, but FBX is even more closed than Collada. Collada has been handed over to a standards group that anyone can join. Alias/Autodesk should really set something like that up if they want to make FBX a competitor to Collada.
In any case, we have enough of a format war right now with BDD and HDDVD, can we just agree on a 3D interchange format?!
BTW, I love that the default background color when you create an XNA project is Cornflower Blue. Why is it that in the games industry we reference Fight Club really, really often? Underlying anger, perhaps? :)