Michigan based Defcom LLC is a new firm that have designed two lightweight grenade launchers which make maximum use of polymers. They are in a sense the Glocks in a world of Beretta M9s.
The DEFCOM XL 79 COMPOSITE is essentially a M79 that has been brought into the 21st century. It weighs 1.41 kg, about half of the original metal-and-wood M79.
The Defcom M79 type product improved grenade launcher receiver, barrel shroud, stock, and front hand guard are manufactured from composite materials. Double action trigger with shotgun-type safety. Matte finish colors: black, desert sand, or woodland green. Top of barrel fitted with MIL_STD 1913 Picatinny rail system. Rear sight is a detachable flip-up scale graduated to 425 meters. Front sight is fixed. Fixed stock launcher has two (2) sling swivels, folding stock has a third swivel mounted on stock hinge. Ambidextrous safety and barrel latch. M16 style pistol grip.
The other Defcom product is the XL 200 under barrel rail mounted launcher. It weights about 40% less than the M203 and M320 launchers.
XL 200 with American Defense locking
latches. instant on / instant off. The launcher drops free when the latches are opened.
The XL 200 opens by moving forward, and then tips up at a 40 degree angle, which allows it to be loaded with the new larger low velocity less lethal ammunition.
The Defcom 40 mm grenade launcher is designed to mount to any Mil Spec 1913 Picatinny Rail system. It has a double action trigger with ambidextrous safety and barrel latch. Barrel tilts downward and locks at end of forward travel to permit loading of all low velocity 40 mm ammunition. Titanium breech face. Trigger mechanism is modular and can be easily repaired in field. Barrel meets U.S. military specifications for material and rifling.
XL 200 mounted on the XL-220 standalone mount.
I will be watching this new company with interest to see how their products do.
The Defcom website is not yet up, but the sales office can be contacted at 559.585.1712
The Army Times reports that the H&K developed M320 will being replacing the M203 in February next year.
The Army plans to begin fielding the first of 71,600 new replacement launchers in February for a cost of about $3,500 each, Audette said. Fielding of the M320 will likely be completed by 2015, Audette said.
..
Each M320 will come with a laser range finder and a sophisticated sight that even lets soldiers know if they aren’t holding the launcher right.

M320 with stock and laser range finder sighting system.
The unit weights 3.57 – 3.89 lbs depending on what rifle it is being mounted on.The stock pictured above adds an extra lb bringing the weight up to 4.8 lbs.
Benefits over the M230 are:
- The barrel swings out allowing larger rounds than the M203. Useful for less than lethal rounds.
- Laser range finder and new electronic sight system which also indicates if the launcher is being held incorrectly.
- Double action trigger

M320 mounted under M4.
The RPG-40 was on display at MSPO 2008. The Centre for Research and Development Equipment Mechanics (OBR SM) and Military Technical Academy, which I assume are Polish organizations, have developed the RPG-40. Despite its name it has nothing to do with the Russian RPG-* arms and does not fire rocket propelled grenades, just the standard 40mm variety.

The RPG-40
It holds 6 rounds and features an oversized chamber so a variety of lethal and non-lethal ammunition can be chambered – limited by how much pressure the weapon can withstand.

Oversized 40mm chamber
It may be in direct competition with the South African Milkor MGL (M32) that is currently used by the Marines in Iraq. It looks like it has a very similar spring-loaded magazine, which rotates after a shot has fired. I would not be surprised if the MGL technology has been licensed.

Marine with M32 MGL (MGL-140) in Iraq.
Photo from Wikipedia

MGL MGL Mk-1
The MGL is a scaled up version of the Striker/Streetsweeper/Protecta rotary magazine 12 gauge shotgun:

Striker shotgun with 12″ barrel. Photo from guns.ru
More info here (translated in google)
I have done my best to find accurate information about this firearm on the Polish MSPO 2008 website. I do not speak or read Polish so I had to rely on Google Translate. If I got something wrong, please correct me in the comments.