The Vita version of Ultimate Marvel vs Capcom 3 will let the handheld act as a controller for the PlayStation 3 version, offering a taste of how Sony could use its devices respond to the upcoming Wii U. Capcom calls it the "ultimate controller" for the game. Considering the touch controls include shortcuts for Hyper Combos and the like, it does seem like that would grant a tactical advantage.
The Capcom Europe blog also gives word that the pocket-sized version of the game will include a Spectator and Replay mode, and Gold Herald color options for the characters. It's shaping up to be a pretty nice package for series fans.
The game released last month on consoles, and the Vita version is set as a launch title in Japan. The Capcom Europe blog says the game will be a Vita launch title in February in the territory, so it's probably safe to say it will hit on launch day in North America too. No official announcement has been made, but we'll update as more information becomes available.