What is not clear here is what about native applications (to run them on the underlying Linux).
This for 3D games and other processor eater applications.
If this is not allowed, how this OS is better than any other OS which has IE and Chrome and FireFox on it?
What about many C++ developers which do not know WebKit? Will they support the new OS?

Not sure if the benefits of no more patches is good enough to propell the OS, because patches OTA and automated install of SPs and firmwares should not create anymore problems on other OSs.

The interesting thing about this announcement is about the NEW WINDOWS system. So it is not linux classic xwindow anymore. What will this be? How revolutionary will be this new window system? Maybe is just a multi-touch window system with growing borders and captions when you want to rotate or drag or resize the windows , and I belive is a vectorial graphics window system.