This is probably the best-case scenario for Democrats that I have seen and believe to be plausible:
This could end up mattering, in that the Democrats might have just lined up a crucial additional vote on some unspecified contentious future issues, and in return they allowed Specter to continue to say that he is not selling out -- for anything other than the seat itself.
60 is a magic number, it seems to me, only if the 60 are all on the same page. If not, the "moderates," the purple Democrats (Ben Nelson, Arlen Specter) and the purple Republicans (Olympia Snowe, Susan Collins) are going to keep calling the shots. Filibusters will typically play out the same way. I know a lot of people were excited about this -- but why?
(It may also be worth noting that Specter was going to lose to his far-right Republican challenger in the Pennsylvania primary. The way PA has gone, that person surely would have lost the Senate election to the Democrat running against him. So at mid-term elections, this is, in a sense, a loss for our side.)