What do you think of Windows 7?

If you have been fortunate enough to try Windows 7 Operating System. What do you think?

Is windows 7 better than XP? Better than Vista?
How is the driver model? Can it run on Quad Core machines?

Windows 7 is looking to be very impressive.And Vista drivers will work for Windows 7.
It's designed to be able to run on laptops so it's very efficient. It's better than Vista (which is already better than XP).