It is my understanding that it will be the basis for the OICW weapon system, which will include a 20mm "smart" grenade launcher. Prior to that, the launcher will be a modular attachement.
The 7mm sounds like a good round, but I'm inexperienced with it. Perhaps if I knew more, I'd be able to form a more coherent opinion.
As for that machine gun, it looks quite a bit like the South African SS-77 GPMG. Noo problem, as it's one of the world's best designs. i hope they didn't change it too much.
AKA the *280/30* of the British Number 9, Mark One service rifle, almost adopted by the Brits at the early midpoint of the Twentieth Century, but paassed over in favour of the 7,62mm NATO cartridge and L1A1 SLR instead. More info *here*.
Not quite, it's based on the FN-Minimi, less the ability to accept M16 magazines, of course, not real practical with a 7,62 NATO caliber beltfed weapon. The Navy also dropped the M16 magazine backup feed requirement for their Mk 46 guns, simplifying the guns at least, with some potential improvement in reliability possible as well. It's one less hole for mud or sand to enter the weapon's receiver, at least.
About the only faults I found with the limited experience I have with the SS77 is that it's a bit heavy for a 5,56mm weapon, not surprisingly since it's based on a 7,62 gun as a basis; the Mk48 took the opposite approach. And it would be nice if the belt feed was interchangable from left to right, as with the M37 Browning and M73 tanker's co-axial guns, helpful for vehicular and twin-gun mountings.