Um, 6 levels of ranger will still give you a 10% bonus to proc off-hand attacks. That's hardly a negligible bonus. Deal.

But not every toon with greater two weapon fighting has Tempest, Zeal, the Fighter Alacrity capstone, or Wind Stance 4 to make up for the DPS hit. And those are the only abilities that these numbers seem to care about appeasing.

For one thing, you probably won't see a barbarian go with two-weapon fighting anymore, ever.

Rogues have little choice, because more attacks mean more sneak attacks, but the -20% offhand still hurts them a lot, especially when not everything is sneak-attack viable to begin with. With trap skills already being potentially the domain of rogue splash builds, other than the mechanics you will inevitably see in mod 5 I can already guess that assassins will be less popular.

Clonks are null for DPS, now.

Favored Souls take a big hit unless they go with Warforged/Greatsword for two-handed fighting.

It just bugs me that the ones taking the biggest DPS hit are the ones who are hardly in the running for DPS of the year, anyway. I don't think it's TWF by itself that's overpowered... I think it's khopesh and multiple speed bonuses that broke the balance curve.