UPDATE: Full roster leaked?
UPDATE:Joystiq has managed to pull what seems to be the full roster of new fighters directly off the Capcom site.
If the information is correct, the 12 new additions are: Strider, Firebrand, Vergil, Frank West, Phoenix Wright and Nemesis for Capcom; Ghost Rider, Dr Strange, Nova, Rocket Raccoon, Hawkeye and Iron Fist for Marvel.
ORIGINAL STORY: Capcom has officially announced Ultimate Marvel vs. Capcom 3.