I would like to take credit for exactly predicting that there would be only 52 votes for cloture. Unfortunately, it is not the same 52 votes that I predicted. More Republicans voted in favor and more Democrats voted against than my quick-and-dirty projection based on the House vote. But ideology still seems to have been a major factor. Democratic moderates Baucus, Lincoln, and Tester voted against (Reid did also to preserve the right to bring a motion to reconsider). Republican moderates like Collins, Snow, and Specter voted in favor.
The factor I didn't consider in the House vote was the behavior of lame ducks (too much work), but defeated and retiring Senators tended to vote in favor (e.g. Domenici, Dole, and Warner).
Regardless of how one feels about the bailout, it is really disturbing that 12 senators didn't even bother to show up to vote.