Actually, I'll just post it here. Looking at Jonah Hex's H&V entry, which is where that skill comes from and it seems that you can just attack with both weapons. You have Ambidexterity, so in theory you can get two independent attacks (meaning two rolls) without any negatives.
I guess I'm a bit worried that for one PP you have doubled your offensive output against a single target which is a bit extreme.
Comparing it to Multi-Attack, MA lets you hit multiple targets, but you get a negative for each target you try and hit. On a single target you get +2 or +5 bonus damage assuming you hit. While that might be a more beneficial for slow moving, high Toughness targets than firing twice, in this game most NPCs have pretty low toughness.
So I'm going to make a bit of a GM call here that Independent Aim can only be used on multiple targets, otherwise you can only attack a single target once. Against a single target Independent Aim (as sparsely written in the H&V) just feels too powerful.
There's also a thread on it here with our very own Badpenny involved, so I'd love to hear his opinion as well.viewtopic.php?f=27&t=43817&hilit=independent+aim