I've been actively playing with WPF and we are currently converting a "machine simulation" ( www.compacsort.com ) over to WPF. I really like it! It's not perfect, but its definitely a big step up from winforms.
I was browsing through...
http://www.orbifold.net/default/?p=713 (need a free ribbon like toolbar?) and he mentioned only around a 1000 people had downloaded kevins bag of tricks and that he was seriously worried about the future of WPF.
Well, I was one of those people to download it a while ago and was impressed with what you could do! so if you haven't already (only 1500 odd people at the time of this post), download from http://wpf.netfx3.com/files/folders/10297/download.aspx
If anyone else has links to good wpf resources, can you point me in the right direction? :-)