So one of my biggest pet peeves with the release of VS2008 was the fact that if I created a WPF project in VS 2008 or even converted it to work in VS2008 - then I was stuck - no more taking that project into Blend to work on the graphics.  This to me was a significant issue.  Fortunately Soma announced that this issue has been resolved and Blend SP1 which supports the VS 2008 project files is now available. Here are the links:
Soma: http://blogs.msdn.com/somasegar/archive/2007/11/30/designers-and-developers-working-together.aspx

Blend SP1:  http://www.microsoft.com/downloads/details.aspx?FamilyID=a07196d1-971b-4710-99c8-d3d9603ccfcb&DisplayLang=en