Update from another Senate GOP source:

as you reported, voinivich is out. its now Specter, Snowe, Collins, and about a dozen Democrats. Feinstein coming out attacking the bill seems to have rattled the Dems and its not clear now what’s going to happen, but finishing tonight looks impossible…

Here’s the video of Feinstein proclaiming she “reserves the right” to vote against the stimulus, and White House Press Secretary Robert Gibbs’s reaction to her comments.