I haven't yet read the licenses in detail, so I cannot say much about them, but more information is available in the (updated) GPL FAQ. The compatibility table from the GPLv3 Discussion Draft FAQ can be pretty helpful, too. There's a Why Upgrade to GPLv3? text and even a video of Richard Stallman (Ogg Theora, transcript available) introducing the GPLv3, the rationale behind it and some of the changes in this new version.
(One nice advantage of the GPLv3 I like is that it's compatible with the Apache license now, btw.)
Probably the most interesting GPLv3 resource at the moment is Palamida's list of projects which already switched to the GPLv3, which includes a number of GNU tools (sed, tar, ed, bison, texinfo, cpio, coreutils) and some other major projects such as Samba. Currently the page lists ca. 140 projects which switched.
It'll be interesting to see how the adoption proceeeds. My guess is that in a few months it'll be hard to build distributions or embedded (GNU/Linux-based) hardware devices without GPLv3 code...
OMG! I would have never believed this if I hadn't seen the videos with my own eyes: Richard M. Stallman of GNU and Free Software fame singing various songs, and Gilberto Gil, famous musician and currently Brazil's minister of culture, jamming on his guitar. Unbelievable.