sorry if this has been posted before but its first demo i saw of vienna and i have to say that whole 3d interface looks like @55 and theres no way thats going to be efficient.
theres already 3d desktop apps like 3DNA and though a short lived novelty, is very slow to open apps as it requires you to walk to the other end of the room, its like a video game that opens your apps, that mistake is the 4 horsemen for microsoft and its enevitable demise on its own.

http://www.youtube.com/watch?v=xfdeNVtGO_A