What didn't make it into the latest Halo? According to the video above by TheHaloCouncil, which shows stuff found in the code of Halo 4, at least two armor abilities.
These would be the "hacker" and "teleport" abilities. The former can undo the armor ability of your targeted victim. Say you deploy your hardlight shield: if the other person activates hacker, then your shield is gone, just as an example.
Teleport, meanwhile, looks kind of similar to thruster pack only it vaults you farther. There's also the possibility that it goes through solid objects, but maybe not. It's hard to tell from the video. Either way, in its current form, it's glitchy as hell—your Spartan might die after doing it.
I kind of love the idea of just undoing someone else's armor ability. And if teleport does let you go through solid objects, then that's also majorly cool.
Reaching out to 343 Industries, a Microsoft spokesperson issued the following statement to me about these armor abilities:
There are many legacy items in any large code base—some that made it quite far in production before being cut for reasons of balance, scope or simple fun; others which were simply prototype ideas that didn't make it far at all. 343 Industries has no plans to add further armor abilities from that code base in any future "Halo 4" downloadable content.
It's too bad we didn't see these armor abilities implemented the game. I would have liked them, at least. Alas, my thruster pack will have to do.