Dead or Alive 5. Tag matches return, allowing two folks to go up against two other folks in a contest of might, both locally and online.
And speaking of online stuff, Team Ninja head Yosuke Hayashi confirmed with Joystiq that the interactive lobbies seen in Dead or Alive 4 would not return in Dead or Alive 5. The reasoning behind omitting the interactive lobbies in Dead or Alive 5 is so that Team Ninja can provide the best, most stable online experience possible. Sure, that's all well and good, but ice-skating crabs.