Specifically? Capcom Heroes, which lets you play dress-up as over a dozen different characters from the developer's history and even wield special attacks themed to those costumes. The Mega Man getup grants an arm-mounted laser cannon. So no, this won't just be superficial stuff like S.T.A.R.S. uniforms from Resident Evil or Chun-Li's trademark garb from Street Fighter. There's even a Ghost Trick outfit.
In addition to that, you'll get all of the add-on packs that've been released since last December (including Super Ultra Dead Rising 4 Mini Golf). The game will set you back $49.99 come December 5th and folks who own the game on Xbox or Steam will get Capcom Hero mode as part of a free update.