I think i know what Halo Infinity is and how is it related to halo 4.

Games Other Halo
1

Infity is a UNSC Ship designed for training(do some research).

So this is directly linked to Halo 4 i think, and beacause why Blue spartans fight Red ones.

So, i suspect Hali Infinity will be a stat tracker, like Battlelog.

2

If Infinity is a stat tracker, then what will be Waypoint?

3

> If Infinity is a stat tracker, then what will be Waypoint?

Those are just my toughs.

Probably MS will implement a system similar to CoD Elite, Stat tracking(free) + early “free” DLC if you pay, ameriting a site.