Sooner or later they will have to make that call. Saturn's rings are made up of multi trillions of moons by your definition (ie anything) and I certainly wouldn't like the job of identifying or catagorising (or naming) all of them!
Most asteroid moons appear to be of a reasonable size to date (most in the 1km+ category though the NEO ones are much smaller). (
http://www.johnstonsarchive.net/astr...idmoons.html#2)
Cheers