According to an article in this months EDGE magazine, you will be able to create your own hero or villain, choose your superpower, and decide how you play the game.
Like traditional MMO’s, your character will level up and you'll develop your powers. When the game starts you might be able to fly, but only later will you learn how to pull off specific moves and attacks in mid-air.
You can’t play as any of the famous DC characters, but you can interact with them, either by aiding or fighting various well known heroes and villains.
Only two environments have been revealed so far – Metropolis and Gotham City. There will also be PvP arenas, and PvE boss battles.
Creative director Jim Lee describes DC Universe as a "kick-ass hybrid between a traditional MMO and a first-person action console game".
DC Universe Online is due out next year.