For 4e I added a disarm feature: Disarm~ With a few calculated flicks of your weapon you quickly disarm your opponent. Standard action. attack: player's dex vs. opponent's d20 roll+dex mod. Hit: opponent's weapon lands five feet away disarming the opponent.
Miss: Opponent get's an opportunity attack against you. Not actually sure if there is a way to disarm in 4e but I'm pretty sure there isn't.
"...and all the people of the world as one voice sang a hymn.The Song of all creation screamed for justice. We are that justice." -unknown bard's final dictation before the last war.-