The Obama campaign calls the video "dishonest." They say Obama has always said that he'd design a single payer system from scratch, if he could, but we're well beyond scratch at this point in our history.
The video evidence seems to show Obama squarely favoring a single-payer system now -- as in 2003.
I asked the Clinton campaign to provide more of the raw footage... so listen to it and judge for yourself.
The political point is that Obama says he's immune from attacks about inconsistency during the general election; if he's found to be inconsistent, or he appears to be inconsistent, it adds information to what voters know about him.