Source: A poster on the NeoGAF forums reported seeing an Entertainment Software Rating Board listing for Marvel vs. Capcom 2 on the Xbox 360 and PlayStation 3.
What we heard: Standing at a synergistic crossroads of fan service and fighting acumen, Marvel vs. Capcom 2 was one of Capcom's last 2D arcade brawlers. Boasting a beefy roster of more than 50 fighters, the game might not have been the most balanced of Capcom's offerings, but it was certainly the flashiest.
But flashy as it might have been, it wasn't online. It was ported to the Dreamcast, PlayStation 2, and original Xbox, but none of those versions allowed for online multiplayer matches. So when NeoGAF poster Shard noticed that the ESRB listing for the game had expanded to include the Xbox 360 and PlayStation 3, the message-board population rejoiced (if the quantity of animated .GIF response posts is any indicator of enthusiasm).
The initial posting lacked any evidence of the listing, which is nowhere to be found on the ESRB Web site at the time of this writing. However, Shard has long been a news-sifting member of the community, and his account was backed by another poster with an apparent screen grab of the ratings site from when the listing was still active. Further into the thread, more posters added to the pile of evidence with screenshots apparently showing listings of Marvel vs. Capcom 2 on menus for PartnerNet, a sort of Bizarro Xbox Live Marketplace in which game journalists under non-disclosure agreements can pull down previewable builds of upcoming Live Arcade games.
Interestingly, when GameSpot checked the ESRB database to verify the post, no such listing was found: not for the Xbox 360 and PS3, and not even for the PS2 and Xbox. The lack of rating for a previously released game well within the ESRB archive's time frame suggests that the game had been listed, and rather than being amended to have the Xbox 360 and PS3 mentions removed, it was taken down entirely.
The official story: "Sorry, no comment."--A Capcom representative.
An ESRB representative had not returned request for comment as of press time.
Bogus or not bogus?: Not bogus, but it might not be coming anytime soon, either. After all, we're still waiting on Die Hard for the Xbox 360 and a host of other ESRB/PartnerNet leaks.