I don't know about commercial sales, but for now it appears that the system would be most useful as an area defense weapon.  The "guns" (if you want to call them that) are rather boxy and so far they haven't seemed to figure out a way to make them more man portable.  This may not be an issue if they are mounted on fixed mounts or on a vehicle.  Another issue I can see that would limit its deployment is reloading the damn thing.  Having a weapon that can fire a million rounds a minute may sound cool, but unless it can be quickly reloaded and unless the reloads are small enough to carry lots of ammo around,  the system becomes little more than a more accurate claymore mine.  Like you, I also like the grenade launcher version.  A pod like mounting on a UAV could be an effective attack platform on area targets, but I presume you could mount it on other aircraft as well.

 

I've seen picture designs for pistols using Metal Storm technology, but it seems that they face the same issue of quick and efficient reloads, and I also have to wonder about ballistic performance.  When you're spraying 9mm rounds at thousands of rounds per second you don't necessarily need high accuracy and range, but when you're firing single shots those things count for everything. 

Grapeshot may be an easier method to achieve a similar result.