Street Fighter IV and Street Fighter X Tekken use their own online infrastructure but for Marvel vs. Capcom Origins—a re-release of Marvel Super Heroes and Marvel vs. Capcom for Xbox Live Arcade and PlayStation Network—Capcom have opted to go with the popular GGPO solution, as indicated by the game’s website.
If GGPO (short for Good Game, Peace Out) detects lag, it compensates for it by rolling back, checking inputs from both players, then going back to the current animation frame. While this may cause jerkiness in framerate, it’s considered more accurate as far as input detection is concerned. Capcom also employed GGPO in Street Fighter III: 3rd Strike Online Edition.
Marvel vs. Capcom Origins will be released in September. Both games will be updated with online play, new achievements, spectator modes and replay-saving.