Interesting stuff alright. That Time Machine gadget sounds like a great idea if they implement it well, which they probably will.

Don't know if he mentioned it in the presentation, but the Spaces tool looks interesting too, seems to be an enhanced multiple desktop paradigm of some kind.

iCal looks pretty cool, some nice improvements there, groupware-wise.

The iChat collaboration stuff is nice, that might have "raised the bar" for Vista, but given that Windows has actually had that functionality out of the box for years, I think they'll manage.

All in all, a fine looking OS, some nice updates there.