I note there is an interesting Fedora thread here on using vga_switcheroo: VGA switcheroo problem - FedoraForum.org … It gets interesting to me around post#5 of that thread.
Edit - it also references a Phoronix forum how to: http://phoronix.com/forums/showthread.php?21979-Hybrid-ATI-ATI-Intel-ATI-solution-small-switcheroo-how-to