i think edge canceled pk fire was mentioned somewhere in the ness guide, and after watching some phanna videos i played around with edge canceled pk fires on pokemon stadium. they're pretty **** hard to do consistently, and if done too early the fire doesn't come out (although ness still yells out "PK Fire!").
given the limited range of pk fire and the fact that it only travels diagonally downward, i doubt this would be very useful since it can only be aimed at certain places in order for it to be canceled. however, the thought of doing pk fire with no ending lag is pretty appealing, especially since that the terrible ending lag is half the reason why pk fire really isn't used at all.
above all else, i think it makes a good taunt =/
given the limited range of pk fire and the fact that it only travels diagonally downward, i doubt this would be very useful since it can only be aimed at certain places in order for it to be canceled. however, the thought of doing pk fire with no ending lag is pretty appealing, especially since that the terrible ending lag is half the reason why pk fire really isn't used at all.
above all else, i think it makes a good taunt =/