As our Good Friend of Federal (or GFOF ) David M. said this morning in an email message, "It was only a matter of time...". Check out this MSDN TV episode on a future Visual Studio designer.
Introducing "Cider": The Visual Studio Designer for WPF ("Avalon") Mark Boulter and Mike Harsh give an overview of "Cider", the visual designer for Windows Presentation Foundation (formerly code-named "Avalon") that will be part of a future version of Visual Studio.
BTW, do you want to be a GFOF (pronounced ga-fof - same sound made while executing the Heimlich maneuver)? I'm starting to ponder the huge benefits incumbent with GFOFness (which is to say I have a good idea for a tee-shirt design). I'll keep you posted on progress.