Ezra Klein runs through the Democrats' options, and comes up with four possible concessions:

1) Unemployment insurance: In a few weeks, unemployment benefits will expire for 2 million Americans. An extension of the benefits commands majority support among Democrats, Republicans and independents. But most Hill observers think Congress will fail to act. It would be unconscionable, however, to let unemployment benefits expire even as the tax cuts for the rich are continued. If Republicans aren't willing to come to the table on unemployment benefits, Democrats shouldn't move on tax cuts for the wealthy. And if they're not willing to take that case to the public, what are they good for, exactly?
2) The debt ceiling: In February, Congress will have to vote to lift the debt ceiling. Republicans are already looking toward this moment eagerly. Sen. Jim DeMint, for instance, wants to use it as leverage for "returning to 2008 spending levels" and "repealing Obamacare." Of course, part of the reason the debt ceiling will have to rise is that extending the Bush tax cuts will cost about $4 trillion -- all of it on the deficit. If Republicans want the tax cuts, Democrats should force them to accept the consequences of their vote and stand shoulder-to-shoulder on the debt ceiling. For Democrats to vote to extend Bush's tax cuts and then let Republicans hammer them on raising the debt ceiling borders on self-parody.
3) Comprehensive tax reform: Our tax code is long-overdue for an overhaul. We need to clean out the loopholes, lower the rates and get rid of the tricks and traps (like, for instance, the occasional expiration of unaffordable tax cuts). The Bush tax cuts offer a useful forcing mechanism for that process: Sen. Kent Conrad has proposed pairing a short extension with a mandate for comprehensive tax reform. If the reform doesn't pass, then rates snap back to their 1999 levels, or deductions start taking across-the-board cuts.
4) The expiration of the tax cuts for income over $250,000: This was originally the White House's position, though they don't seem to be fighting for it very hard. Now it's the position of the House Progressive Caucus. They want to split the vote on the tax cuts for the rich from the vote on the tax cuts for income under $250,000. It's widely acknowledged that this makes the passage of the tax cuts for the rich less likely, which is why Republicans are ferociously resisting it. it's unclear exactly what leverage they're wielding in that effort, but whatever it is, it seems to be working.

Can anybody doubt they'll go with option 2, self-parody? I mean, "letting Republicans run up the debt and then blame Democrats for it" is the whole centerpiece of the Democrats' fiscal strategy over the last three decades.