Below is what appears to be an Autodesk Produced video on some of the technical changes to the REVIT 2011 product line. * The video kept jamming on me so I skipped ahead and it worked.
If you don't have time to watch here's the poop in a nutshell:
1. YOU NEED A CERTIFIED GRAPHICS CARD.
(the list is yet to be published, REVIT 2010 did not produce this list)
2. You will be able to download a utility to check the compatibility of your current card and driver.
3. The 32 Switch for 32 bit systems causes crashes with hardware acceleration graphics enabled.
4. It's all about the new certified card + hardware acceleration.
5. I suspect we all need to go 64bit with the certified card at this point in the game.
6. Rendering Materials is common across AutoCAD, REVIT and MAX so the interface has changed and working with old projects will probably cause problems with materials. I personally think the materials nightmare between the apps is not over yet.
7. No more limit on the processing 'core' requirements. Both Dual and Quad core should work for rendering performance.
8. FBX export to MAX from REVIT 2011 only works in MAX 2011.
9. Worksets have been re-written on the inside.
10. You now have visibility graphics control of worksets through a linked file.
11. Personalized 3D views that 'appends a newly created 3d view's' user name with your name.
12. Sync with Central performance has improved.