The PDC was fun (who doesn't like free laptops), but not as energizing as previous years. Many of the announcements were just refinements of things previously announced.
The new Silverlight 4 stuff looks promising, as do the new features in Entity Framework 4.0. I'm also interested in trying to pry the IQueryable serialization stuff out of RIA so I can make use of it in a more typical distributed system situation. RIA is explicitly designed to try and hide the distribution tier (which I understand for the scenarios they are targeting), but the data services stuff is too cool to leave it limited to that.
I had several good talks with different Microsoft folks about EF, MVC, and F# among other things. Now that all the session videos are online almost immediately, these in-person interactions are the main draw of the conference (well, that and the laptop).
Having the conference end later in the day Thursday was good, since it made me stay until Friday and gave us a chance to head to Santa Monica Thursday night and dip my toes in the ocean. We arrived right as the sun was setting and immediately forgot about all the stupid traffic on the way there.