Well, after much delay, I finally got my desktop rig back up and running.
And surprise! The problem was exactly what I thought it was. Once I got into Safe Mode, it was just a matter of uninstalling the video drivers and reinstalling some new ones et voila! Everything is tickety boo.
Note to self: Never update video drivers via the MS Update website. Something like this happens all the time.
At least I got all of my pictures backed up this time. If it dies now, I can cremate it without shedding much of a tear.