For some reason I am under the impression that falling prone was errata-ed from a free action to a minor action but I can't seem to find it. Am I dreaming this or what?
Falling prone has always been a minor action in 4e. Dropping a held object is a free action, which has caused confusion among some players that I know.
It does seem odd that falling down requires an action. But I suppose the next time I encounter a gap that's too wide for me to jump, I'll just run across it. I mean, I won't fall unless I spend a minor action, right?
It could be possible (in a Looney Tunes sort of way) with a readied action, which works as an interrupt. You say, when the bard heals and slides me, I'll charge that guy. Bard heals and slides you over the gap, your interrupt triggers before you fall and off you go charging!
A minor action is really not much time... just try it a few times how fast you can drop without hurting youself too much, or breaking stuff you carry around...
also as a free action you could do it to interrupt incoming missile fire...
There was a thread awhile back about and item or feat or whatever, that allowed a character to get up and shift 1 as a free action... and the OP had come up with an 'abuse' that would have worked by RAW... if falling prone was free.