It looks nice. I wouldn't be able to easily coordinate all these finger gestures, though... not with one hand, and certainly not with two. The 1-pointer-approach of a mouse is less sophisticated, but this is exactly its advantage... no coordination effort required at all.

Also, I think their window layout is a solution to a non-problem. People usually, in 99% of all cases, work with fullscreen windows and switch with Atl+Tab or click on the Window representation on the bottom (in MS Windows). There is no mess, no cluttered window space. Those who want windows of various sizes side by side or on top of each other and overlapping want to keep control. Being able to choose between vertical/horizontal/mixed arrangements is a benefit.