Emerging Community
One of the hardest parts of Kodu was launching without a central community. It's a long story; buy me a beer next time you're in Redmond and I'll cry into it for you.
What we have been betting on (big time) is that communities will start to self-organize, and they are. My favorite right now is http://kodu.moco.net, which is packed with very active, knowledgable creators. Lots of people are offering up their gamerTags and saying "share with me!" There's even one that's acting kind of like a server. Get in there!