As usual, members of the Phoronix Forums community have been quick to monitor AMD servers looking for new driver releases to discuss. They are now playing with Catalyst 12.8 but for Linux users there isn't much in the way of exciting changes.
Catalyst 12.8 is based upon the fglrx 8.982 release, which is sad. The disappointing Catalyst 12.6 for Linux was also based upon the 8.98 release stream so in the past two months there isn't much in the way of changes.
The only official change for this new Catalyst 12.8 Linux binary is production support for Ubuntu 12.04 LTS, but there's already been suitable 12.04 "Precise Pangolin" support previous to the 12.8 release.
Meanwhile, internally at AMD and within their closed beta lists they've already been onto the 9.00 stream for several weeks. However, it looks like AMD is giving the more recent driver code greater time to bake before sharing it with the world.
If you want to try out Catalyst 12.8 for Linux x86/x86_64, the download link is available here.