The Steam icon in the task bar offers you the latest drivers, but what they do not tell you is the "Express" install, just installs the Catalyst stuff but does NOT install the driver so the crash on start still happens. Instead on install choose "Custom" then Select All then install. Once finished if you go into the display driver properties you will see the date of the driver is 3rd October 2011 and now the game will work.
I am running it in 2560 x 1440 and its quite awesome and very fast

Cheers
Nic W