In Iraq we are using 155mm (Which is the normal Artillery for Armor Troops). Since the 1960s 105mm Howitzers have been restricted to Light Infantry (Including Marines) and Airborne Infantry for the 155mm gives twice the blast as does a 105mm round.
The 105mm Howitzer is the lightest Howitzer in the US Inventory at the present time (We do have Mortars that are smaller, but with much less range).
In today's army you use the 105mm when you are going into terrain where movement by Armored Vehicles will be restricted. In this I mean Rural terrain, Urban Terrain like the actions in Iraq do not qualify for the 155 Self propelled Howitzer can just stay outside the urban area and drop shells all day long. Thus I do not believe these guns are for Iraq.
When it comes to the US Army they are three areas that the 105mm towed Howitzer would be preferred to the 155 Self Propelled (or even 155 towed) those are Afghanistan (Which if we wanted them the Army would have demanded them 2-3 months ago so they would be ready for the Spring Offensive that is about to get underway), Haiti and Columbia (With Venezuela a possible fourth area, and let not forget Nepal which is about to fall to guerrillas).
All four of these Countries have large Rural area where Guerrillas hold up in rural areas far from areas where you could take any Vehicles let alone an Armored 155mm Howitzer. The 105mm can be hauled by Ship, by Truck or mule, and by Huey size Helicopters (Including the Black hawk that succeeded the Huey in US Service). TO transport the heavier 155 M198 you need a heavier and most costly helicopter than the Black hawk or Huey.
This sounds like someone either wants these Howitzer in one of the above areas OR the US plans to go into one of these area and want adequate artillery Support.
I lean to US intervention or need, for these guns were for other countries usage, the US could have given away older M101A1 or M102 Howitzers (The M102 is actually lighter than the M119 and thus easier to move around, the M101A1 and M119 are about the same Weight but the M101A1 dates from WWII while the M119 is what is being issued since the late 1980s).
When My old National Guard Division was preparing to switch from being an "Infantry" Division to an "Armored" Division, the old M101A1 105mm Howitzers where to retired from our unit but than re-built before being put into storage. Thus we have plenty of M101A1 and M102 Howitzers. Thus I do not see these Guns being needed for use by our allies. If we needed 105mm for out allies we would give them the M101A1 or M102 Howitzers NOT the M119.
That leaves use by US Forces. We are taking about FIVE Guns (A Battery has Six, a Battalion has 18). You should not mix guns in a unit, the firing tables (which are used to make sure the guns hit what you what them to hit) are complete different between the M101A1, M102 and M119 (Mostly do to each having a different length of the Artillery Tubes which changes the velocity of the Round). Thus if you need more guns to fill out a Battery or Battalion you need the same gun that unit is using NOW.
As to the tin foil guys who are reading this, an Artillery piece without the support system (Firing tables, aiming circles, and other mechanism to control the fire of the guns) is almost useless. They are better anti-tank weapons out there and any guerrilla might be better off using any spare artillery rounds you have as improvised mines (Like the Iraqis are doing) than as artillery Rounds in any anti-tank role.
My opinion, this is to fill out some unit that has damaged some of its M119s and need replacements (The only reason that would be would be the lost of M119s somewhere in Afghanistan, probably by accident or maybe enemy action) OR the Army is building up a New Battery and/or Battalion to support some action in Columbia, Haiti, Venezuela, Afghanistan and/or Nepal (I lean to Columbia and or Venezuela for Haiti is small enough that 155mm Howitzer could cover the whole Island from about 3-4 fire support bases thus US Army would use 155mm Howitzers in Haiti).
Information on the M101A1 (Claims US Marines still have 248) Weight 4980 Pounds:
http://fas.org/man/dod-101/sys/land/m101a1.htmInformation on the M119 (Weight 4520 Pounds):
http://fas.org/man/dod-101/sys/land/m119.htmhttp://www.army.mil/fact_files_site/m119/index.htmlFor Information on the M102 (Source say the US Army has purcahsed 1150 of these but many were lost in Vietnam and shipped ot other countries): Weight: 3004 pounds
http://fas.org/man/dod-101/sys/land/m102.htmhttp://www.army.mil/fact_files_site/m102/