You're all talking as though this is a new thing.
Dual wielding has always had much better attack bonuses than sword and shield, but you sacrifice the extra defense that the shield gives you. So you either dual-wield and kill them before they kill you or use a shield and wear them down.
Yeah, it should not be harder to balance than any other combat style.
I'm in agreement with Dracolich that high Dexterity should be required for optimal dual wielding.
Also, dual wielding should make you attack faster. So you can attack once with each weapon at the average AP cost of the two weapons (or a bit higher).
You sacrifice the defensive bonus of shields and raw damage of two-handed weapons for faster attacks.
