Nate has a good take:
Some of this is Baucus's chickens coming home to roost. When you make a unilateral decision to negotiate with only five other people from a 23-person committee and 100-person Senate, and two of those five people have clear electoral disincentives against supporting any plan that you might come up with, the negotiations are liable to end in failure far more often than not. The flurry of on-the-record statements against Baucus's reform plans -- not "leaks", not trial balloons -- points toward a defective process.
And that may suit Democrats just fine.
I suspect we will see a few more twists and turns on this yet - and even a left-liberal revival.