I don't know how ME3 can get any simpler, TBH. It's a shooter, the most prolific genre in gaming and no actions in it stand apart from the rest of the genre that could make it "too complicated to learn". You have your guns, your melee, and your grenades, all the ubiquitous elements of the genre that's been booming since the 90's. ME doesn't have that problem for the player because it's pretty much your conventional sci-fi shooter. Finding it too complicated is like finding it too complicated from switching from analog to digital.
And the other guy is right, there's no way they'd drop biotics when they finally have a decent engine. Given what we know of the game and the engine they have, I'd wager they'd start implementing the environment into combat more than a couple of exploding barrels.
I don't think DA, the franchise that completely, and almost completely, revamped its gameplay between instalments should be looked at all when considering ME. It obviously went through its own problems with how it played that ME doesn't have.