Just wanted to bounce this off here because there is such a solid technical crowd...

My graphics in WoW have been doing similar artifacts to this for quite some time, it used to be rarely and it's stepped up to more and more often. I run a 7900gt with a zalman copper cooler on it, the cpu never budges on it's temp and it's nice and low (I don't recall the temp right now, but I did research it before and it was well below what anyone considered too hot)... the card isn't overclocked, blah blah...

Anyhow, an example of the corruption:

http://www.botbh.com/images/corruption.jpg

This will come and go during gaming sessions. Last night for example with 3 copies of wow running I had this on one copy of it. After 3-4 minutes it went away. Other common distortions have to do with names, textures flicking light/dark... the world textures looking like auto-glass through a polorized lense (checkerboarded), etc.

I'm pursuing an RMA at this time, but wanted anything else I may try... I've ran the gambit of drivers and updates, etc.