I feel that if Armour Abilities were removed completely, then the players would be divided. So I thought that instead of removing them, they could be simplified to the basics. These are my ideas:
Sprint: Relatively the same as Reach, but for a slightly shorter time.
Jump Pack: Similar to the jetpack, but it only gives you a short 'burst' of power into the air for a very short time. It has a higher acceleration into the air than jetpack.
Active Camo: It will render the user completely invisible, but only for a short time. There'll be no interference on the radar, but you will still appear on it as usual.
Drop Shield: I'm not to sure about this one, and might just leave it to the above three. It would work in the same way as it does in Reach.
I have left out Armour Lock (I think most people will be happy if it's not in Halo 4), and Hologram (it isn't that useful). Evade may also be included however.
These are just my ideas for what would make most people happy, tell me what you think!
EDIT: I'm mostly refering to Multiplayer, so any reference to canon is irrelevant.
[Edited on 06.17.2011 3:29 AM PDT]