Interestingly, the combat action description for drawing a weapon says, "Drawing a weapon so that you can use it in combat..." There's no option for a drawing a weapon that you will not use in combat.
The problem with that viewpoint is that it creates a conflict when someone wants to fight with two weapons and yet not use two-weapon fighting. In other words, consider someone with a BAB of +6 and only having a longsword in hand. He tries a disarm, fails, and gets his longsword disarmed in return. For his second iterative attack, can he do anything like quick draw a second weapon and attack? Is this a situation of "fighting this way?" If not, and I hope you'll agree not, then how is this situation any different than the attack of opportunity? As an attack of opportunity, IMO, you are not "fighting this way" (i.e. with two weapons at once in order to gain an extra attack per round).