I'm happy (but surprised) to report that both the proprietary 100.14.09 "nvidia" driver and the free latest-git "nv" driver are now working on my 17" MacBook Pro.
The only difference between now and when I last reported is that I upgraded from 2GB to 4GB yesterday, which I didn't expect to make any difference re: working video, obviously. In fact, I hadn't even bothered to boot into GNU/Linux since performing the upgrade. But after reading this thread:
where the original poster is having problems with a 4GB machine, I wanted to see if I could reproduce his problems.
To my surprise, the X server started up just fine on the built-in display. I was using the git version of the "nv" driver, so I switched to "nvidia", restarted X and everything continued to work. Since then, I've cold-started the machine and the X server came up perfectly using the "nvidia" driver. I haven't tried yet with my external LCD display hooked up, but I will a bit later.
Here's my bug report log with the "nvidia" config, and the Xorg.0.log from the "nv" config. Hopefully these'll help you figure out what's going on with the 2GB machines.