Caught part of a show on Discovery last weekend called "Future Guns."  Of interest was the OCSW, the Objective Crew-Served Weapon, which fired 20mm airburst projectiles and was computer controlled.  It looked evil indeed.  The manufacturer was testing it and had it rigged for remote control.  They claimed that the OCSW and one 50-round box of ammo had the same lethality as a .50 M2 MG and something like 8 boxes of ammo.

They also had a bit about the OICW, and they showed how the assault rifle part detached from the rest of the OICW and could be used separately.  Pretty neat but without a buttstock I don't know how useful it would be.

The current sniper rifle made an appearance as well, as did the M16 series.  All in all it was a very informative episode.

I've seen those new infantry prototypes.It has the current 5.56 nato on the bottom and the explosive projectile weapon on top, kinda like an over/under shotgun?

most certainly a mean mother!