Senate Democrats, lead by Bernie Sanders, appear to be whipping votes to break a Republican filibuster of healthcare reform -- but, at the same time, giving conservadems the latitude to vote against the bill.
In other words, if the Senate Democrats can get secure their entire caucus and achieve 60 votes (including the interim senator Governor Patrick is due to appoint anytime now) to break the filibuster, some of the centrist Democrats can feel free to vote against final passage of the bill when only 50 votes (plus Biden) are required. No reconciliation swiss cheese, the public option would pass a floor vote, and the Blue Dogs would have political cover. It's win-win.