According to The Wall Street Journal, Democratic Senate aides say there's a "60% chance" that senators will try to pass the finance portions of health care reform using Budget Act rules, also known as reconciliation, which would allow them to bypass the requisite 60-vote cloture filibuster. The threat of reconciliation has always been on the table, but it's mostly been buried under a slew of objections from Senate Democrats, in particular, like Kent Conrad, the chairman of the Budget Committee, who doesn't think it feasible or wise. White House officials haven't taken an official position, but Vice President Biden, for one, is skeptical is leaning toward the approach.
It takes 113 pages for the Congressional Research Service to explain budget reconciliation. I'll try to spell out the relevant rules in a paragraph. Basically, in order to prevent Congress from using the process for issues other than passing a budget, rules in the Senate (named after the fastidious senator from West Virginia) allow anyone to challenge any provision in the reconciled bill that is "extraneous" to the goal of dealing with taxes or entitlements. A 60 vote majority is needed to reject the point of order, which takes effect if that threshold can't be reached, thereby dooming whatever part of the bill to which a senator objected. The Byrd rule itself is fraught with ambiguities. The Senate Parliamentarian, Alan Frumin, would be asked to determine whether the provisions in question are subject to a point of order. Rules and precedents here are very complex, and there is certainly no "one answer."