Hmm, yes and not.
On the plus side, I think the gameplay has improved and story mode is quite awesome (aside from the filler-esque boss fights).
On the down side, the roster is fairly disappointing, combos and stages have been removed, and online is still as bad as it's always been.
Personally, I'd recommend that you wait a bit for the game to lower in price. It's definitely not worth full price, imo.