It looks like something is going on with Halo, as MarkMonitor, Microsoft's usual proxy for claiming domain names, has started registering domains that all revolve around the phrase "Halo Infinity" and "multiplayer".
The domain names claimed by MarkMonitor include "HaloInfinity.net, HaloInfinityMultiplayer.com; HaloInfinity.org; HaloInfinity.co.uk; HaloInfinity.mobi; HaloInfinity.de; HaloInfinityMultiplayer.net; HaloInfinityMultiplayer.org; HaloInfinityMultiplayer.co.uk; HaloInfinityMultiplayer.mobi; and HaloInfinityMultiplayer.de." Other sites claimed include "spartanops.org" and "Morethanjustamap.com."
This could be many things. It could be Microsoft's replacement for Bungie.net's Halo stat tracking. It could be a new map pack for Halo: Reach or Halo: Combat Evolved Anniversary Edition - or even Halo 4. Least likely but still possible, it could be the name of a new Halo multiplayer-only spinoff.