There are a lot of really cool possibilities with this.
For example, non-lethal, possibly very effective offensive tactics: Imagine facing off against the Iranian Imperial Guard; a C130 flys over and drops 30,000 semiautonomous microdrones. Controllers (sitting in their warm, dry, comfy control center back in the US) direct the swarm to descend on the enemy lines and simply harass the s h i t out of the soldiers.
Imagine trying to aim and shoot when you've got a beehive of small buzzing drone crashing into your head, face, buzzing around blocking your field of view, etc. Could be very effective, if electronic countermeasures can be dealt with. In fact, this would be a great way to deploy ECM against the enemy, jamming their GPS reception for big guns, and lots of other stuff.