So, I love the idea of adding something more to physical classes, and I think this is a great way to start that conversation along...dead post or not. However, I do have this to say about Xunnie's suggestions, call them my 'edits' to said suggestion.
Xunnie wrote:
To further even the playing field on this - it should be a skill that only certain races/classes can have. Example: Barbarians, imo, should not get the use of dual wield because it is more an agility skill than strength skill - and the typical image of barbarian is someone with brute strength that would rather have a sword as long as you are that they use to basically swing with raw strength to batter you into submission (or death). The elven races however, imo, should be allowed this skill because they are known for agility. What they lack in strength is made up for by the use of two blades.
Classes would be tricky. Warriors/Knights/Warlords/War Mages - no. Knights gets shields and should be able to use a shield in a fight. Warrions - warlords - war mages ... they have brute strength (and in the case of a war mage .. spells as well). Thieves, Rangers, Mist Raiders - definitely. These classes rely on agility instead of brute strength. It is feasible to see them with two weapons and fighting with them.
I actually disagree with the opinion on Dual Wielding with stats and classes. Barbarian's in most fantasy games, are actually the lightly armored raiders that use two handed heavy weapons OR one handed light dual wielded weapons just as well, but beyond that...Dexterity is wonderful..for moving quickly, or taking aimed range shots. HOwever, when it comes to wielding two weapons...Strength is all that matters. Be as lithe and quick as you want, wielding a pair of daggers...but to hold two swords that way anywhere from 5-15 lbs each, and one in a 'off hand' is difficult, and takes a lot of strength. As well, Warriors would be completely something within the field to do such. A sword and an axe. As well, shield...where as they are armor...are also weapons, and take a lot of control and skill to use in your off hand. So even a knight could make sense. Now I also agree, that thieves are known for daggers, and many of them. I would say it would require class skills or something, or even a qualifying stat depending on the weapon. High Str means dual wielding normal/heavy weapons, high dex dual wielding light weapons? Just my two cents.