Party combat? Final Fantasy XIV has it, being an MMO and all. A new preview from the alpha build of the game shows off Levequests and party combat. You can take a look at both below:
Square point out that the enemies shown in the video are of a low level, and that the battle system is currently undergoing significant revision. Also, the battle music you hear in the video above is different from what is currently in the alpha build of the game.