Check out the HOL for the WPF. Its a great way to come to grips with the new features of WPF. I have already completed "PRSHOL08: Creating Rich 2D and 3D Content with Windows Presentation Foundation" and "PRSHOL03: Creating Custom Controls with Windows Presentation Foundation" and found the labs an invaluable way to get up to speed on things.
Why not have a go and try some of the labs out? (BTW, is you missed PDC'05, these labs are exactly the same ones they had at the conference.)
Windows Presentation Foundation Hands-On-Labs