You can't block while using two weapons, which makes no sense, since you can block with one weapon and no shield just fine.
You don't swing any faster while using two weapons, unless you take the perk that lets you, which still doesn't even make it that much faster.
I'm sure I'm not the only one that's noticed this: There's no animation for drawing/sheathing your weapons while dual wielding! It just uses the single weapon animation, and the off hand weapon just sort of pops in or out of existence.
I'm definitely glad that Bethesda decided to include dual wielding, it's certainly a big step in the right direction, but it seems more like an idea to be improved upon in TES 6 (which I very much hope they do!) than a realistic play style in Skyrim.
Sorry if this sounds like a bunch of whining, I'm just trying to share my opinion on the matter.
What are your guys' thoughts?

