After speaking to a Hill staffer, the nuclear option roll call is as follows:
As it stands this moment, all 44 Democrats are solid against it, as is Jeffords.
McCain and Chafee are against it.
Eight other Republicans are wavering. We need four of them. I'm trying to get a list of the swing voters, but I assume it includes some of the Senate traditionalists, like Stevens, Hagel, and Lugar, as well as some of the New England moderates.