WPF will be supported on Media Center AND will be remoted out to XBox 360 and other Media Center Extenders.
Lot's of exciting new changes for MCE Vista- but none that have not been announced already.
So to recap- two ways of extending MCE
1. Media Center UI Langauge of sme sort (what MCE team use to buildtheir UI)
2. WPF
Showed MCE RSS Client Platform Sample- will be available as surce in SDK. Lot's of 3D. Think it's using the MCE UI language-but looks just like WPF- i.e. gratuitous Video projected on 3D surfaces.
Showed Electric Red Nascar portal. Uses WPF- very rich. Very cool. One of the best WPF demos so far. Lots of Video.
Have a ListView demo... where the List View Items are full figure driver cut outs! Yee Haaa! [I have a photo of the screen which I will try to post later]