The screenshots scare the bejesus out of me, for one simple reason: the upper-right tic-tac widget to turn off that godforsaken toolbar is missing. So I'm glad it's fake. The video doesn't show that part of the screen, though.
I hope they let you save sets of tabs. It'd be nice to open my apps folder and have all the sub-folders I use for sorting available as tabs.
I've wanted tabbed folders (not the same as tabbed windows, which can contain any number of different folders) since OS 8. Looks like I still won't get them, but I guess that's okay.
I have to admit, though, I'm scared at the very idea. Not because I don't think it's a great idea; I do. It's just that ever since OS X first came out, Apple has had a habit of taking great ideas, implementing them badly, and using them to replace things for which they're not suitable replacements. Basically, Apple's lost my faith. Spotlight was the final nail in that coffin.
(I was about to say "and why is Safari now Aqua", and then I realized it's not Safari, but Internet Explorer. WTH?!? Edit: Oh, it's supposed to be the Windows version. Cute. Obviously fake, but cute. I didn't realize before because macosx.com crops it off and doesn't let me scroll.)