Destructoid was sent an interesting tidbit of info on the surfacing of a MadCatz-manufactured "Marvel vs Capcom Tournament Edition Arcade Stick" in the database of shopto.net, a UK-focused online retailer. The description goes on to sound like it's the same design as the 360 version of the TE stick that MadCatz put out alongside Street Fighter IV, with Sanwa parts, a headset port, USB connections, and, of course, the price.
While the item name doesn't specifically drop MvC2, the description does:
The official Marvel VS Capcom 2 Arcade FightStick Tournament Edition controller for Xbox 360 was designed for fighting game fans to recreate the quality, gameplay and precision found in Japanese arcades. Using the exact Sanwa joystick and 30mm buttons found in official Japanese arcade machines, along with realistic spacing and an eight-button layout, the Marvel VS Capcom 2 Arcade FightStick Tournament Edition brings the true arcade experience right into your home. Featuring the same award winning layout of the Tournament Edition stick, along with official Marvel and Capcom character artwork, the MVC2 FightStick TE is the perfect compliment to the hectic fast paced combat. With separate turbo settings for each button and the best components, prepare yourself for hours of competition, no quarters necessary.
Added to the ESRB rating leak that mentioned MvC2 on Xbox 360 and PlayStation 3 back in October, it makes for a pretty compelling--if unconfirmed--package. Could Marvel and Capcom have re-teamed for a re-release? Would they really release a joystick around a downloadable release? Would Capcom really re-team with Marvel without also making a deal that included new comic book crossover fighting games in the future? Guess we'll have to wait and see. Capcom's having an event in the relatively near future. Perhaps some news on this topic will come out of that event, but obviously nothing official has been made officially official at this time.
[UPDATE] Armor42 pointed out in the comments that achievements for this game have surfaced over at X360A. While that's still not enough to call it "confirmed" or whatever... that's a pretty clear sign that this is happening.
Also, I'm required by law to embed this video whenever MvC2 is mentioned: