Just for clarification, for anyone who might be stumbling on to this thread late in the game, we seem to, once again, be crossing our wires and talking about two different problems in this thread. Granted, both of them are graphics related which, no doubt, continues to lead to the overlap.
Problem #1: Is this: http://support.apple.com/kb/TS4088. Intermittent black screen or loss of video, or similar such symptoms. This has, largely, been identified by Apple as a hardware issue, specifically with the Nvidia GPU. Apple are, on their own dime, replacing logic boards on affected models as a last-ditch solution.
Problem #2: Graphics corruption (what this thread was, initially, intended to address). Symptoms have, typically, manifested as graphical artifacts appearing on screen to varying degrees and blocky drop shadow rendering around windows. The symptoms have, usually, occured when the Intel GPU is active. Toggling over to the discrete GPU clears the artifacts. This has been show to be a software issue. For many of us, the problem was nonexistent until we upgraded to Mavericks. Has Pehtis's solution has proved, the problem is directly related to the memory compression feature introduced with Mavericks. 10.9.2 has, largely, solved this problem. Though it isn't 100% there, yet.