Mehrdad is looking for some WPF books.

I know of two:
  1. Programming Windows Presentation Foundation
  2. XAML in a Nutshell

...and of course, Chris Anderson is busy working on his book.

I expect that once Beta2 hits the road, we'll see a lot more books on WPF and WinFX.

I can't wait for Beta2...much cool stuff to show off.