Microsoft announced today that Mechassault 2 was being worked on, for a winter 2004 release. New mechs, new levels and especially a new type of exoskeleton much like Halo's armor that will certainly change the gameplay a lot.
@Sdarts: also says chapter. Like it's not a full experience. So we are getting this game with Chloe and some 3-4 hour uncharted 4 story DLC which might cover Sams story for example? (3 minutes ago)