The Commitee seems to have a lot of powers, they have lots of information about humans, and they seem to know about our future (They "know" spartans is the key to victory). They can be forerunners (i dont think so), they could be some sort of AI or robot (possible), they could be an unknown race (possible), they could even be The Precursors (possible). Regardless of what, i think there is lots of more hidden in the data pads and all switches.