I'm usually against re-releasing the enhance version of the same like what Capcom did with MvC3, but since this game was awfully rushed I'm willing to pay $40~$50 for an enhance version of what the game intended to be.
If they do make a new version, it must have Talim and Zasalamel in it, support or include the previous version's dlc. Have improvements in Single Player, either training challenges, character endings, better story or some new fun mode.
Namco has the gameplay and online portion nailed in the current version, they just need to beef up areas that many find lacking and at least add missing styles. But I don't think Namco will release another version of SC5 sadly, once all on disc DLC has been released we will have to wait a few years for the next installment.
Like Street Fighter 4, the first version will be training wheels for most and then for the next version, everyone starts off with a clean win/loss ratio.