Metal Storm is still developmental, but I would bet that some may get used in Iraq.  The biggest problem that I see is the ammunition.  It is non-standard, so any kind of testing would have to be a complete package.  That is not only the Metal Storm launcher, but significant amounts of ammunition to feed it.

 

The Metal Storm uses electrically fired cartridges with self-consuming propellant (for cases).  This kind of ammo is not in the DoD procurement chain.

 

The design is revolutionary because it completely eliminates the mechanical process of feeding, chambering, firing, extraction, and ejection of conventional ammunition.  This is a good thing because you don't want your firearm to jam in the middle of a firefight.