Check out the screenshot of the "ribbon" in Office 12.
Those of you that like the "flip feature" in Vista, may want to check out Expose in OS X or one of the many Windows clones.
But I'm not going to point out each and every item that Vista copied from OS X. The marketing folks at MS are expecting people to make those comparisons. They've pre-trained their minions to ignore those comparisons. I'm just excited that Windows is FINALLY getting a lot of the features that I love about OS X in the actual OS instead of as third-party tools.
update: Here's a screenshot that shows the similarities between the new look of Office 12 and iTunes new look.
Brent Simmons (of NetNewsWire) had some great comments when the new look of iTunes made it's debut. My favorite was the comparison to NeXT. He also notes some trends that he's seen in the latest OS X apps. From the looks of Office 12, maybe those design trends aren't specific to OS X? Notice the margins bounding the Word window? According to John Gruber, this new look is so bad-ass that it doesn't even have a name. The only thing that O12 is missing is the combined title-toobar. Well, that and getting rid of the Aqua buttons. But I kind of like them.