I've managed to get bumblebee + bbswitch + nvidia drivers configured after a bit of toil. The remaining issue is whatever I run with optirun seems to hang up after resume from suspend or hibernate, and I can't unload the nvidia driver and power down the discrete card until reboot. A nice temporary solution is to inhibit suspension and hibernation when I'm using the discrete card.
So far, I've got a little wrapper that invokes
optirun "$@" and loops moving the mouse with xdotool until optirun terminates. This does the trick, but I don't want to prevent the screen from dimming. I'd like a solution to prevent suspension and hibernation ONLY, hopefully avoiding anything involved with gconf or writing config files.