I had this same problem happen on my MBP not too long ago. The strange thing is that my mouse cursor was fine but the rest of the screen was a rainbowy static that changed only slightly when different UI elements were redrawn (like staticy profile of a dialog box when I tried to do a "blind" reboot with the power button + r so I could clear up the problem).
After reading around the web a bit, I tried the suggestion in
this article about changing the sleep mode to 0 on my MPB and the issue (knock on wood!) hasn't resurfaced since. I liked the faster sleep/wake up style of the older Apple laptops, and I save any critical work frequently anyway. My hunch is that the graphic state didn't reload properly (from disk?) after sleep, so this sleep mode change would bypass that.