Both Nate Silver and Charlie Cook have the race as a toss-up, while political scientist Charles Franklin puts Scott Brown in the lead:
no matter how you slice the data, the only reasonable conclusion is that Scott Brown has moved from well behind to a lead somewhere between 4 and 11 points.
Franklin’s analysis is the most interesting that I have seen because he looks at the overall data plus he clusters the polls (i.e., the sources of the polling: Democratic, nonpartisan, leaked, etc.). Reading this race via the polls has been quite difficult given the proliferation of polls from previously unknown pollsters (many of which have clear partisan leanings).
The only caveat he offers is:
Sphere: Related ContentPolling special elections is hard. Tuesday we’ll see how hard, and who was good and/or lucky.