It'll start small. Mostly noticed by jobbers trying to get product through Customs. Then one by one, over the next few years the different states will legislate the same definition into their dangerous weapons laws. I have no doubt they will be strongly encouraged by Homeland Security issuing back door talks concerning the decreased availability of grant money to states that don't bring their laws more into accordance with Federal policies.
The best chance for us consumers will be when some jobber, or end consumer, suffers a confiscation and he/she decides to fight the new regulation in court.
Many, many, Americans on juror rolls don't even own a folding knife, or if they do it is often an older model such as a Buck 110, a Swiss Army knife, or maybe even their old Boy Scout folder. Let's hope sheeples don't comprise the bulk of a jury on that case. The government will no doubt introduce 'expert' testimony showing how criminals prefer knives that open easily. Maybe try to work in some video re enactments of actual crimes done with such evil weapons and maybe try to present examples of some of the more vicious looking ones as evidence of what needs to be banned to protect the innocent children of America, or possibly offer a get out of jail free pass to a convicted felon to testify as to how all the members of his posse/gang/club really prefer Leeks or other assisted opening knives as the best way of killing nuns, competitors, police and any witnesses. Only a Judge or a Juror who has a one handed knife of their own will recognize the BS when they hear it. If you haven't been donating Leeks and Tactical folders to the members of that old church down the street (whose members probably get to be on a jury 4 or 5 times more often than the guys who spend their weekends in the local pub) then the BS will probably be believed. If however, the judge has a Kershaw Leek in his pocket and the jury foreman normally carries a SOG daily, then our chances of a ruling that the new restrictions and the definition are unconstitutional become greatly improved.
It's like gunlaws. When the sheep believe no one but violent people wear one, then the sheep see nothing wrong with banning them. If however many sheep have one and the sheep realizes they are after their gun, then the law won't pass.