Back in October of last year, an ESRB rating first revealed that Capcom was evidently planning to release a port of their beloved crossover fighting game, Marvel vs. Capcom 2, for the Xbox 360 and PlayStation 3. There hasn't been any more news on the possibility since then, but now no less than two pieces of information have practically made it official: Xbox360Achievements.org has posted a list of (what else?) twelve supposed Achievements from the 360 version, and Siliconera reports that MadCatz is planning to release a new fight stick based on the title in July.
The Achievements look pretty standard for a fighting game, and with requirements such as "Win 100 Ranked Matches online," they also confirm the obvious inclusion of online play. Other Achievements involve building teams modeled after the X-Men, Darkstalkers, and Avengers.
As for the new stick, Siliconera reported that UK retailer ShopTo.Net had a listing for a new arcade stick from MadCatz based on MvC2, set for release in July (possibly indicating a time frame for the game's release as well). As you can see now, though, the listing only says that the product "no longer exists in our database" -- although you can also still clearly see that the page's title at the top of your web browser is "Marvel vs. Capcom Tournament Style Arcade Stick - Microsoft Xbox 360." If this was a sly attempt to redact evidence, they didn't exactly do a thorough job...
So obviously, all that's missing at this point is confirmation from Capcom, Microsoft, or Sony that the game is actually coming. With all the building evidence suggesting it is, we wouldn't be surprised if a confirmation wasn't too far off.