It is clear after watching this video, there is more driving the left's opposition to ObamaCare than just that the public option is out. For example, Hamsher said in this interview that Senator Lieberman was acting on behalf of the the White House for drug companies and insurers, after she attacked the bill for raising the costs of heath care. (FireDogLake agrees with Howard Dean: Kill the Senate Bill.)
According to The Hill, Senators Feingold and Sanders have still not said they will vote for the bill. Burris has said he will vote against if the bill does not contain the public option.
From a purely power-politics point of view: the left must have at least one or perhaps two Senators represent their view of killing the bill if they want to be taken seriously in the future. If they roll over and play dead, or can not produce one No vote, they will never be taken seriously again (and will be viewed as a paper tiger) -- especially given the fact that there are plenty of serious policy beefs the progressives have with the Senate ObamaCare bill.
The progressives are likely making a shrewd political decision: on one hand this bill is so unpopular that it will hurt the cause of health care reform and their push for a single payer system if it passes, and on the other hand, the bill is so bad that it is better to leave the status quo and use the health system's existing problems as a pole vault to pass a single payer system. From their point of view, it may take longer, but in the end, it is a much smarter strategic decision.
My guess is that the progressives will post more than one NO vote from within the Democratic Senate caucus, and ObamaCare will die.