I think that we'll all be completely blown away by this game once we see it.
I think that once we see it we'll be completely blown away by the fact that we have nothing. No places to eat, sleep, use the facilities, or anything. What this means is that we'll prolly see asari returning, because they're so well... Matronly. So, we've gotta get all that settled before we can move on to anything else, like making an economy that works for everyone. What this means is that we'll prolly see volus returning in ME:A. What this means is that point two ties back into point one. An oxygen rich atmosphere wouldn't work well for a volus. So, therefore, you've gotta find a home for them as well.
Then you've gotta make an economy. So, what to make first? Well, I'm thinking mining is first up on the list. Without metal you can't have anything, weapons, armor, spaceships. After that, I'm thinking weapons are first on the list. What this means is that while krogan have a strong and redundant nervous system, vorcha are likely gonna be the name of the game here. Without weapons, you can't do anything. Then armor. But you're free to go with whatever you choose. With weapons, you can take over starships. With the converted starships (and I'm thinking Titanfall in space w/ destructible environments) you can have Spaceports and used starship dealers.
And all that's just the base game, or at least it is in my head. Then you've got the mysteries of Andromeda and all the races there and how to communicate with them. So, all in all, I'm thinking that this game is gonna be a very "from the ground up" kind'a game. And I'm kind'a excited.
EDIT : Add to this a kind of faction system that is based off'a how much you hear the enemy saying relates to how much you can understand them. That would very cool.