I've seen it played, but haven't put my hands on it. It's gorgeous, especially the skies. The main part of controlling the character looks like pretty standard 3rd person stuff, but it's a bit more than that. I'll be buying the extra-choice special edition whatever set to get the artbook.
I loved the hell out of Psychonauts, and any Schafer-haters can go ahead and sac-gargle me.