I'm getting some interesting results from playing with the two intel graphics drivers (i810 and intel).
i810 - needs 915resolution for mode setting. If it runs out of memory it turns off 3d acceleration. intel - handles mode setting. If it runs out of memory it crashes. So: With the intel driver, I can't get it to run two monitors unless I can figure out how to give it more graphics memory. With the i810 driver, I can only get 3d acceleration on one of the two monitors unless I can figure out how to give it more graphics memory.