some quick news, if you haven't already heard about it. Mass Effect 3 has a new single-player DLC called "Omega". i've gotten it and played all the way through it. its about 4 missions long, and you don't get any of your ME3 squadmates with you this time. instead, you'll do the majority of the missions side-by-side with Aria T'Loak and a new character to the ME universe.
all in all, it took me about an hour to complete each mission, so there's a sizeable chunk of gameplay here. there's two new enemies to combat, but most of the enemies are the familiar Cerberus variety. the story plays out pretty well, but its nothing spectacular. the best aspect of the story is how much my paragon character contrasted with Aria who is, predictably, very much a renegade.
the main complaints that i had was a number of animation related bugs during cutscenes, and a noticeable lack of music during the last cutscene altogether. otherwise, gameplay was up to par with the vanilla game, which is to say that its excellent. combat was equally good as it was consistently challenging throughout. the locations are superb and highly detailed, and the environments are laid out naturally.
all in all, if you're a fan of the way ME3 plays, then Omega is a very good DLC pack that will give you about what you'd expect and perhaps a bit more. if you're one of the people that wants to completely write off the game because you didn't like the ending, then Omega isn't likely to change your mind. for me: 8/10.
See the struggle of the faithless lot as they negate their time
How low to sink to the depths of their frame of mind