As far as the tanking goes, I'd come up with my own build and it holds magnificently against dungeons, world bosses, everything of the sort.
Though, I decided I wanted to keep a second bar for DPS, just so that I wasn't completely incapable if I wanted to do solo play. ( I usually play with my girlfriend, and sometimes another friend, who are more DPS oriented.)
Currently, my second bar is 2H DPS, and what I'm wondering is would it be more beneficial to switch to dual wielding or a bow, and mix either of those weapons with a few of the DK powers.
In this bar (currently) is
Noxious Breath
Green Dragon Blood
Ash Cloud
Executioner
Wrecking Blow
[Ult[- Standard of Might
Would a combination of dual wield and DK powers be better, or would using bow/powers be better than the 2H Setup
Note: I'm finding ash cloud to be god awful in dungeons, and for any DPS/DOT in my opinion.