The preconference session on WCF by Juwal Lowy was very interesting. Most WCF-talks focus on the mechanics: how to edit the config-file, what to do to use a specific protocol. Juwal instead demonstrated the productivity gains WCF brings to the platform.
Interesting quotes / take aways:
"The first law of Xml: if you see xml, you're doing something wrong"
Nobody cares about you doing plumbing ... so don't do plumbing.