I was going to start my own topic on this, but you've covered the basics.
Gnome 2.14 was just released yesterday, take a look at the
release notes (this is a very nice graphical tour, far different than your typical release notes).
This release has added the following features which either rip off, or are inspired by, Mac OS X, depending on your perspective:
- Searching in the file manager, functionally very similar to Tiger searches
- Searches can be saved, a la smart folders
- Deskbar, Spotlight clone
- Fast User Switching from the panel
Deskbar looks nice; the functionality surpasses Spotlight in some ways.
Also though not a part of Gnome, this xgl stuff has just recently come out which enables hardware-accelerated X and again, mimics Mac OS X in many ways -- drop shadows, an expose clone, video playing in icon mode, transparency, and also a variety of other effects not directly inspired by Mac OS X.