...but she won't be having anything stronger than an E Tank tonight. After all, she's ten. But seriously: a new mode for Ultimate Marvel vs. Capcom 3 has been revealed at the New York Comic-Con, called "Heroes vs. Heralds." It seems that the purpose of this mode is to assemble a group of heroes to combat a team of Silver Surfer-ized fighters who, we assume, have been granted the Power Cosmic by Galactus in order to serve as his heralds.
This mode uses different collectible character cards to unlock new moves, and among the characters featured is none other than Mega Man's sister, Roll. The trailer has not been officially released yet, so far as we can tell, but you can view someone's shaky-cam recording of it below:
Apparently, this mode won't be included on the retail release, but will be available as a free download following the game's launch.
Thanks for the tip, PStart!
Update: And thanks to word from Unknown and a picture from thegolfcourse, who was at the panel, we can see that Mega Man X is another card, too. How many more will there be? We'll bring you word as it comes.