I really don't know how to evaluate the MA Senate race. If you're interested in predictions, you can go check 538. Some recent polls have Martha Coakley ahead, some have Scott Brown ahead.
Right now I'm emailing and facebook-walling to make sure all my MA Democratic friends know that the special election is January 19 and there's serious risk of a Republican winning Ted Kennedy's seat. Special elections generally involve very low turnout, which (1) makes the results unpredictable, (2) means that one vote has an unusually large impact on the outcome, and (3) means that the number of eventual nonvoters who could've been talked into voting is much larger. Under these conditions, an individual's vote and get-out-the-vote activism will have an unusually large effect.
I imagine that Massachusetts folks reading this blog are politically active enough that nothing is going to keep them away from the polls -- many of you are probably making sure that your people turn out to vote on the 19th. But out-of-state folks can have a big impact as well, just by making their less active MA lefty friends aware of what's happening and its significance. There are major negative consequences for health care reform, climate change, financial regulation, and basically everything we might want to do in the next year if Martha Coakley loses. With the advantages of incumbency and weak economic conditions, we can't be certain of winning in November and averting 6 years of Scott Brown causing trouble from a seat that should be a reliable Democratic vote. Don't let this happen.