If u saw the screen shot post above!" 84 detailed halo4 screenshots" i believe forgive me if im wrong but u now what i mean lol!
If u notice theres 3 boxes on the top right its part of the hud! And if u read the bulletein the part about the health. "The HUD shown in the gameplay clips lacks a health bar. Will this change, has this changed, or will Halo 4 use the same health system as the one in Halo 2 and 3? –Gravemind
Health has been changed. There are no health pickups, but we’ll have more news on how that system works in gameplay at a later date."
_______________________________________
1st theory: one of those 3 boxes i feel is for grenades , second box can be a health regeneration where as to reach you use it an have to wait some time to use it again. The third can abilitys .
_______________________________________
2nd theory : those 3 boxes can be those customisable loadouts they mentioned an my 1st theory would be the loadouts jus three diff ones!
_______________________________________
Leave ya input plz