Dual wield adds 19% miss chance to white hits (?) so basically you could take average DPS of 2-hand weapon and compare it to average DPS of two one hand weapons (50% penalty to off-hand) - 19% of that.
For pure white dps, not taking any talents whatsoever into account, it comes out as a very slight win in favour of 2-hand. So slight that its negated by using 2 levels higher one-hands. (i.e. 2x lvl green 24 axes will do more white dps than green lvl 22 two-handed mace)
But when fury talents are added into mix, Dual wield specialization + Flurry, that slight advantage of 2 handed weapon vanishes. (otherwise everyone would use 2h at 60 level for dps too, no?) and dual wielding two one-hands start to do MORE white dps than same level 2h.
Then there are other perks of dual wield: 1) Smoother rage gen and more rage generally since you do more damage 2) less oh-shit moments when your slow 2-hander misses twice in a row
I dont think difference is big, but for me it seems like dual-wield fury simply does more damage when leveling, and has smoother gameplay, assuming same level and rarity weapons.