Behold! The Future of Windows!
I suppose then that Snow Leopard will be a "preview" of Windows 10?
On a slightly more serious note, it does appear that Microsoft has learned from the Vista debacle, which is commendable. They've taken the teething issues of Vista and decided to improve upon it instead of trying to drastically reinvent the wheel again.
The interface, from the various screen shots I've seen, does look like the bastard offspring of an unholy Aqua/Aero union, but there is time to polish it up. I'm not keen on blotting up the desktop with widgets, though. If they were "borrowing" from the Mac OS playbook, they could have gone whole-hog and made a Dashboard (though Apple would let that stand for all of 10-seconds).
The sort of interesting dilemma Microsoft has in borrowing so much from OS X is they do give the impression to the average man-about-town that Apple had it right all along, and Microsoft is trying to play catchup now. That can't be good.