The thruster pack is an armor ability that will be available in Halo 4. Essentially it allows someone to catapult themselves laterally, and the uses are myriad. Maybe you want to get out of a situation. Maybe you want to grab a weapon quickly. Maybe you’d like to get a better view. There's probably a bunch of other uses I can't think of that we'll see once the game is in the public's hands.
Since revealed at E3, the ability has undergone many changes. At first it seemed to be that activating the ability would cause the screen to flash for a second, and then you’d go in the direction you were aiming–it was good for coming around corners, but you couldn’t really jump gaps and you’re left vulnerable. An interesting ability to be sure, still.
In the PAX build, things worked a bit differently. Notably, there’s a new animation that occurs when you activate the ability. It looks cooler than “screen goes white,” so there’s that. Instead of flashing, you go into third person mode, showing where your Spartan is launched to, then snaps back into first person mode. The visibility you have, therefore, is heightened: you can see behind/around you while its activated. Moreover, it seems as if you have some vague control of how that thrust moves, but it doesn’t seem too significant. It also seems as if you can thrust into the air–but only as far as the Spartan would be able to jump normally.
Both versions of the thrust armor ability have a recharge time of six seconds, which seems absurdly fast. Maybe this’ll be changed, but overall, the changes look as if they were for the better.
Source: Halo 4 Examined: Thruster Pack Changes
