I feel for you man. I'll be part of that in the coming year. Marketing wants to migrate our intranet to it and they want us to do it.
Shouldn't be to bad though.
I can tell you this much: I've deployed the beta as well as the RTM of it, and I've got a *fairly* good handle on it.
However, the documentation is still a mess. even though it's technically been updated to RTM status, there's still stuff in there that either doesn't make sense, or isn't applicable.
Further, there's definitely a goddamn bug with the way it checks names against Active Directory. For instance, if I let it resolve my username, it pulls up something like c:OL1|TRUE)KINGS\jamesomeara instead of KINGS\jamesomeara. Everything *seems* to work, but I'm convinced that this is the cause of some of the weird problems I'm having.