I use ATI R5850 HD 2gb VaporX (Sapphire) and AMD Vision Engine Control Centre with Catalyst v12.3 that was updated on 16 march 2012 (to 12.3) via 'check for updates now...'!
As others have noted, Switch of AA an AF in Skyrim and set them both to desired point in CCC/ECC (do not use application settings) and this should take care of the pixelation issue until it is fixed by AMD/ATI.
The issue is known by AMD/ATI and is due for fix in next driver update. Sorry I not got the link to hand - but issue is in driver notes!

Curious that I have v12.3 via ECC and did not specifically dl it as a beta or such!