Does it actually do more damage though? From what I can see, you still attack as fast as you would with 1 weapon. I personally pick my fighting/weapon style based on what I like and who I imagine that character is, it has absolutely nothing to do with the actual stats (the same applies to what armor/clothing and weapons I use).
Obviously I don't expect Bethesda to change anything. I know there will be mods for it, just gotta be patient.
depends on the weapon you choose. Standard mantra is to always, always use a dagger in the offhand, as the dual attack speed (RH & LH together) is dependent on the speed of the offhand weapon. now, you can further increase overall attack speed with two daggers. focusing on higher criticals in the one-handed sword tree (I assume this works for daggers?) would greatly improve damage on top of attack speed. Also, there is a shout that greatly increases attack speed, but it has a woeful cooldown time in my experience.
I've personally always been a fan of higher criticals when it comes to mele characters, so I try to focus on that whenever possible. There are weapon "enchants" that do this, but from what I can tell, you can't actually learn them and apply them yourself. Very very sad. Though the one that I have obtained ("+25% critical" on a dagger given to me by an NPC after completing a quest in Falkreath) would probably be way, way OP if you could stick that on two ebony daggers. it would be nasty, though.
Though, as always, I'm sure there's a mod for that.
I like the armor ignoring damage with maces, too, but I don't like how slow they are.
EDIT: I think I misspoke earlier about stamina for DW characters. I believe the dual attack is stamina dependent, and is basically the main reason for going dual wielding. You still get more damage with overall normal attacks (potential of two weapons with up to two enchants, each), but those dual attacks are also much stronger than the other mele power attacks. You get some rather awesome decapitation animations when going DW, as well.
about that decapitation perk--I'm glad that it's actually useful. usually (In Fallout games) that type of perk does nothing but add a fancy animation. This one gives a percent chance that you will have an instant kill. Pretty awesome, as it's saved me tons of grief with mobs where I need to clear out some low-level scum quickly so I can focus on the main "boss."