I'd say as many as you'd like. I mean how many free actions can one get in a round? I'd disagree with 2 per round though, since there are many situations where you can get more than three. Like if you are hasted, have a quickend spell, and a 5 foot move, or if you have expert tactician, take a 5 foot move, you couldn't draw a weapon with your quick draw. It should pretty much be common sense though that a person can't use quick draw all 14 longswords and then drop them.
jake