If it's anything like that shitty Omega DLC, it'll be 2 hours long.
The ME3 DLC is either shitty, day-1 ripped from the main game content or shitty, shits all over the series even further lazy, bullshit, short DLC.
Both are terrible. Fuck that game.
I'll rate them like (sort of) Bhamv did ME2 DLC
Prothean - Insultingly ripped from main game content shitty
Extended Ending - Insultingly fuck you, our endings weren't shitty so we'll add nothing useful to the endings shitty
Reaper origin - We decided to lame-ass the Reapers even further shitty, also it's super expensive and short shitty.
Omega - Remember how we hinted at Omega in the vanilla game? It's 2 hours long and 15 dollars shitty, also we were too lazy to record any new dialog except for Shepard so you can't bring any crew members with you...not even Joker, he doesn't fly the Normandy in this.
Citadel - I don't know, but I do know if there's anything I've learned about Mass Effect 3 so far, it will be shitty and short. And holy shit I just watched the trailer. Fuck this fucking game. HEY, YOU NEED TO BE HELPING EARTH. NOW BUY SOME DLC WHERE YOU GO ON DATES ON THE CITADEL. FUCK.
I would have paid for DLC that removed Kai Leng from the game. He is the worst fucking character in all of Mass Effect.