If you own an HD 2900 XT you should definitely check it out, since that graphics card is on top of the to-do list for ATI's driver team. If not, it will depend on the games you play and how many months have gone by since your last update.
Before downloading it, take a look at the release notes (performance improvement department):
"Half-Life 2: Episode 1 and Dark Messiah Might and Magic performance improves on the ATI Radeon™ HD2900 XT Crossfire configurations. Improvements of 16% or more can be seen with HDR enabled."
It doesn't sound like much, but TweakTown and Technic3D have tested them and, as usually, OpenGL performance is improved.
As for bugs fixed in this release of the ATI Catalyst™ Software Suite, the list is rather long, specially the one for Windows Vista.


No, not the game, only the internet site for now. But if they decided to get it up and running, the game release can't be far behind.
GT HD is supposed to be a taste test of what is to come from GT on PS3 and it successfully does this but it's not going to last you more than a few hours. On offer is one track and ten cars with only one car available initially, where as more become unlocked as you beat the various track records with each car. Generally, even without the driving aids on, you will unlock most cars within one lap of the circuit and then it just becomes a piece of software to show your PS3 off to mates. 