At this point it’s pretty much an open secret that the next piece of DLC for Mass Effect 3 will be based in or around the Citadel. It’s also been suggested that the majority of the voice acting cast have been brought back for it, which means either a lot of characters will be showing up, or new lines are needed to cover all the possible squad permutations.
Either way, thanks to BioWare’s Casey Hudson and Mike Gamble, a pair of images relating to the DLC have found their way online. The first shows a Vegas-esque strip, complete with Casino building, while the second is an armoured dude with a huge blunt instrument (perhaps an antagonist of some sort, and most likely a Krogan.)
Since it’s still only semi-confirmed, this DLC doesn’t yet have a release window or a price attached to it.