Overall Marvel vs. Capcom 2 is still a fantastic fighter. There is nothing really innovative about this title, however, there isn't supposed to be as this is simply a faithful recreation of a popular fighting title. If you loved to play this title in the past then you should be able to pick it back up like you never left. Moves and combos will start flooding into your memory within a few minutes.
If you are new to the series then you should also definitely give this game a try. The controls are really tight and feel great. Just be sure to utilize the training mode before you fight online or you might find that you won't last very long.