Always had threat problems at malygos and patchwerk. Now that i am dual wielding, i dont. So next to looking cool, i also get some love from 25 people. That should give you enough reason to dual wield? :P
Untill now, the boss encounters are to easy, i could prolly tank naked get tea and still survive, since healers never get oom anyway.
I think the REAL benefit or suckyness of dual wielding will come when there is some hard content and more gear to choose from, like in the Sunwell content patch.