The character roster for Marvel vs. Capcom: Infinite has reportedly been leaked by way of a post on NeoGAF. According to forum user Ryce, who has a solid track record of leaking Marvel vs. Capcom: Infinite details, the list will include a mixture of series mainstays and newcomers from both companies.
As noted by Ryce, the leaked list of Marvel Vs. Capcom: Infinite characters is currently missing a character from the Capcom side. The other characters are as follows:

  • Arthur
  • Chris
  • Chun-Li
  • Dante
  • Firebrand
  • Jedah
  • Monster Hunter
  • Morrigan
  • Nemesis
  • Ryu
  • Spencer
  • Strider Hiryu
  • X
  • Ant-Man
  • Captain America
  • Captain Marvel
  • Doctor Strange
  • Gamora
  • Hawkeye
  • Hulk
  • Iron Man
  • Nova
  • Rocket/Groot (It's unclear if it's Rocket Raccoon with Groot assisting or a redesigned character actually called Rocket/Groot)
  • Spider-Man
  • Thanos
  • Thor
  • Ultron
Fans have noted the lack of X-Men characters; speculation suggests this is part of Marvel and Disney's ongoing efforts to shift the focus away from these characters, as the movie rights are currently with Fox. Although Marvel is positioning the Inhumans as the replacement for the X-Men, there aren't currently any Inhuman characters on the roster.

The characters named above certainly seem like they're picked to leverage the popularity of Marvel's Cinematic Universe. GameSpot has contacted Capcom for a statement on the leak.

Capcom has announced a release date of September 19 for the game on PS4, Xbox One, and PC and revealed a $200 collector's edition.

Source: GameSpot