I was having a conversation with another player earlier and we got onto the subject of how a few classes know have some sort of knockback abilities: (Typhoon for druids, etc.) and I think that the move kick should have some sort of knockback effect as well.
My logic behind this is that rogues must have strong legs since not only can we fall farther (I'm assuming its our legs that absorb the impact) but we can potentially run on water. Granted its not for long, but when is the last time you saw anyone walk on water. It seems like it would require at least some sort of training of the legs.
This brings me to my next point, that a kick should knock someone back. It certainly has that effect IRL (yes I realize this is just a game). I've watched the animation, this isn't some little sissy kick to the shin, its a full blown roundhouse to the chest or face (depending on the race). One would almost expect a kick like that to have some sort of physical affect like being knocked back.
In conclusion, I know that this will most likely never happen, and if it did it would most likely be a glyph or talent or some such thing. However I think that if it was added, it would certainly fit,as well be appropriate for the class. Not only that, but the move would have some potential use against non-casters as well. I just had the idea and wanted to share it.