Neil passed me some of these URLs in my comments and i'm all too happy to republish them.
New things in the 3D stack in WPF. Overall a smooth integration of the 3D tools released last year, but baked in rather than using a parallax trick.
Gives all the details about the changes. Of big interest to me, as I've toyed a bit with the AddIn namespace, is the plug-in architecture. I'd like to see if the passing of Visuals respect cross process isolation, especially in version independent scenarios. Oh the possibilities!
- The user control persistance bug is fixed too in both 3.5 and SP1. Double great news.