I wish they would go back to the old control scheme. The one they introduced in AC3 completely ruined the gameplay (along with the horrible world design).
I think they should do three main things, as far as on foot gameplay goes:
1)
Just carbon copy Batman's combat: They haven't patented it, steal it, who gives a shit?
2)
Make the Parkour faster, more responsive, but give the player more agency: Right now it takes too much time to climb around, yet it is all so automated, that you end up going in the wrong direction half the times, because the game didn't understand what you wanted to do.
I'm not saying something on InFamous levels (that's far too flimsy and lacking in momentum and weight, not to mention automated), but more intuitive and that made you feel more agile.
3)
Just completely revamp the stealth: Social stealth is total bullshit, when your brand REQUIRES for you character to be dressed with the
Assassin's official uniform™, so either revamp that whole thing, or just stick to more classic "don't be seen" stealth and lift several pages from Splinter Cell Blacklist, which is in-house anyway.