I hope ME3 will be a cross between the previous two. A tad more role-playing qualities with maybe a bit of an inventory, a more diverse and... flexible (or something) story, but have the intensity of this one.
And a slightly better planet scanning system (and a bit more anomalies on the planets, more semi-irrelevant side-quests).
And I wouldn't have believed I'd say it, but I miss the old elevators
I'd rather watch a bit of movement and listen to news reports in an elevator than look at some loading screen with blueprints and stuff. Also, as a review pointed out, it takes away from the immersion and movie-like quality of the game. (in the same context he also mentioned that the clip-system emphasizes the game-quality, but I don't mind that so much. I like it more than the overheating)