A few months ago I was writing a great deal about the performance issues that were uncovered in Beta 2 and our efforts to address them.  As a result of your feedback and help the product we have now released is TREMENDOUSLY better.  Thank you. In those posts I talked a bit about work we were doing to improve drawing performance.  Some of the issues were sub optimal code in VS and others were missing optimizations in WPF.  Moving VS to be a heavy WPF user certainly put a lot of strain on WPF and was really a great way to help mature WPF quickly. Jossef has written a blog post on a bunch a of the WPF performance improvements in .NET 4.0.  Many (but not all) of these were driven by the effort to make VS an awesome WPF app (and indirectly by your feedback on VS performance).  Check out Jossef’s post to learn more: http://blogs.msdn.com/jgoldb/archive/2010/04/12/what-s-new-for-performance-in-wpf-in-net-4.aspx

Brian