Even though it will be a long time before we play halo 4 here are some Armor Abilities that i know will be in
Hologram - Can charge forward to distract the enemie
Jet Pack - Sends you soaring through the air
Active Camo - To stay hidden
Forefunner Vision - to let you see through walls
Now as we all know the one Armor Abilitie that will not be here is sprint. This is because sprint is now a standard ability available at all times. I hope this info helped and i will be posting more thank you.