The WPF 3D team started a blog a few days ago ... and today they released some code to be host interactive 2D controls in a 3D surface..
You can find all about that at their new blog here
Amazing stuff that could have saved a few of my projects ( e.g. OTTO Store ) a lot of time ... I hope it saves your new projects some time... and it allows you to create some truly wild and innovative experiences..
The video interview from karsten & Ernie ( includes demo + explanation ) is here
PS -- To those that went through the effort of creating 2D interactive in 3D world , we had our share of late nights and beers.. what more can you ask for? (translated, "sorry, this did not exist until it was too late for you" )