"Will it be so new we won't like it..."
That perfectly sums up today's average gamer. I don't want to be another one of those *~old gramps voice~* "Back in the day we used to have fun with what we had *cough cough*" people, but it seriously annoys me that people can't enjoy things for what they are anymore. Just let it get to you, take it in, and enjoy it.
We are so spoiled with choices, that we always go "but it could be that way" instead of just going "ok, that's new, that's cool!".
Back to topic.
From what I've seen in the gameplay "leak" video, with the jetpack, the game is going to be massively open. Sandbox open? Maybe. People exclusively looked at the guy, his animations and the jetpack, but there was actually something really interesting on the UI itself. On the top of the screen, there was a compass like interface, similar to Skyrim, where the mako was marked as an icon and something else, maybe a mission... who knows. So from that I take a wild guess and expect us to wander through huge open landscapes, because I wouldn't need a compass in a COD like level, and I know that everyone's going to hate me for saying that, but ME's level design, in the past, was way too narrow for an RPG.
So this will be something to look forward to, although I've seen people saying they prefer to play on a rail than in an open world... *shivers*