I'm glad to report that I'm testing a beta driver that has completely fixed the tearing on my DisplayPort monitor, a problem that I have been suffering since I got a 6970 in 2010. I bought a couple of 7970s back in January and the problem persisted, but now it looks like AMD has found a fix. I can't test it on 6xxx cards, but on my 7970 the problem is solved.
If all goes well and no major issues are found, this driver should be public next week so it can be tested with multiple cards/monitors configurations.
Today AMD will announce a change in its driver development schedule: there won't be monthly Catalyst releases starting with Catalyst 12.5 (which won't exist). They have decided to focus harder on quality and improvements vs regular updates which may not bring many new things. This way there will be no need for two separate driver development paths every month: one to get the official WHQL driver and another that keeps doing the regular driver development. We should expect more "hot fixes" and "preview drivers" when new games are released or urgent fixes are required.
UPDATE: It looks like some plans have changed and the fix is already available. Please, try it and post here if it fixes tearing for you.
Downloads:
Windows 7/Vista
Windows XP
Linux