Yep, I saw one demonstrated at the Naval Weapons Support Center at Crane, Indiana a few years back. It looks to me like they've got an immediate future as a defense against incoming sea-skimming missiles like the Exocet, sort of a continuous shotgun defence such attacks. I expect that'll be one of the first practical applications for the concept.
And with land mines falling out of favour for area defence, remotely triggered Metalstorm mortar launchers have a serious application for denying critical locations such as bridges, mountain passes or desert-area waterholes to unwelcome visitors. Metalstorm offers a swell opossibility of differing warhead mixes for such projectiles to be used, depending on the target configuration.
And though I doubt we'll see a Metalstorm application in the small arms field in the near future, the possibility that something along the lines of a multishot M79 grenade launcher but with the punch of a Light antitank weapon, possibly using a ring airfoil grenade, is certainly a more likely bit of useful kit for the poor bloody infantryman than the OICW now appears to be, and it should be quite usable in urban or built-up areas in MOUT operations, as well, a *master key* for doors or walls where access is immediately required.
-archy-/-