Don't mind me, I'm just consolidating all of my Halo 4 posts from various threads into one mega-post of Very Bad Ideas and updating my little weapon list from yesterday to be easier to read / less terrible (but still probably pretty bad). Enjoy.
I wanted to include some degree of AA-like function because I honestly like the variety they bring to the game, just not in the way they were implemented in Reach. It also touches on my comment earlier about certain Halo weapons starting to feel redundant or pointless; AAs can be something extra to differentiate them from other weapons that are too similar in form or make a cruddy weapon suddenly have a more desirable function. Covenant weapons, for example, really need something to make them distinctive again. I also like the concept of having a Secondary Fire mechanic but don't think the standard implementation would work for Halo.
The important part is that the abilities are now paired exclusively with weapons, limiting the potential for abuse. No more Active Camo + Sniper Rifle bullshit. Here's a revised version of the chart I posted last night. Click to enlarge.
Additional examples, possibly on Forerunner weaponry;
Overshield-on-Demand
A weapon could generate a small "Overshield Pulse" when activated; your shields temporarily gain a small amount of Overshield for a few seconds when activated. This provides a sort of metagame; knowing when to pop your extra shield boost while bearing down on an enemy would require a great deal of skill to judge. Too soon and they just chew the extra shield up, too late and they chew you up. This would be an interesting dynamic without the cheapness of Armor Lock.
Stealth Generator
Would provide a very short duration Active Camo effect. This effect would be married to a weapon that can't be abused quite as much as the Shotgun or Sniper Rifle could in Reach. Something like a Forerunner pistol with a small clip to reign in the abuse.
Rective Hologram
One weapon could utilize the Hologram effect from Reach, as it was great at faking enemies out. Additionally, if an enemy actually shoots the "reactive" hologram, it will create an on-screen 'ghost' of an enemy, visible even through walls, that shows where the shooter is at. I'm seeing this on the Forerunner version of the Assault / Plasma Rifle, something they'd use to set traps.
Flood-Absorption Module
The Forerunners in Halo 4 will be very old and likely have spent a lot of time pondering their enemy, the Flood. Perhaps they will have adapted part of the Flood's unique biology to produce a weapon that has organic elements that can be used to heal the user. To prevent abuse, the heal effect would have a very long cooldown or would consume a significant chunk of health. I can see the weapon having flamethrower-like properties; short range but not quite melee-range like the Shotty/sword.
-----------------------------------------------------------------------------
Thruster Dash:
Finally, the Armor Ability button is replaced by a thruster-based "Dash", as seen in the Halo 4 Teaser. This is essentially Sprint made a default ability, but with quite a few options on functionality.
-----------------------------------------------------------------------------
Yes, I have too much time on my hands. Back to the Guild Wars 2 thread with me.