I've been at this for 2 days now and haven't been able to come up with a solution. The first time I upgraded from 12.04 to 12.10, I rebooted, was able to login; but, had no window decorations or Unity toolbar. I was using closed drivers at this point. After many attempted fixes with no avail, I just reinstalled.
I am now at a fresh install (with the 12.04 CD, then immediately upgraded after install).
GRUB's "nomodeset" has at least been able to me into the tty's and has told me that tty7 hangs after:
apt-get is fully updated to my knowledge.
Begin: Running /scripts/init-bottom ...
Graphics card is: nVIDIA 260m