You can increase the attack speed of 2handers with the blacksmith craft. You can also end heavy attack animations by following it with executioner (reverse strike) giving you a nice nearly instant two hit combo.

It also has the reach to power attack an enemy outside of red circle power attacks. (haven't tried on dual wield).

You have a nice heal with Rally (momentum).

I only tried dual wield in beta for only a bit. I can't tell you which is better so I'm just listing some of the strengths of the 2handed line. I think there is value there even outside the CC.