just saw this story on cnn ... no moving parts, potential to fire a million rounds per minute in certain applications... the Pentagon is loving this...

http://www.cnn.com/2003/BUSINESS/06/26/australia.metalstorm/index.html

For infantry/armor use, I'd say it's a waste of bullets.

But working on ships or battery installations, then I could see a use for them as with gattling guns.