wyvern targe at least occasionally sells on the AH.
As far as /drg, seems like the standard max haste gear for dnc is 21%, so you would only gain 4% max more haste, add in vbelt and that's only 2%. Obviously you could swap gear, but considering your main incentive is already marginalized does not bode well for the combo.
Basically before 75 it's completely viable as a sub given targe and earring. 6% haste is pretty substantial, which would be on top of swift, samba, and maybe spell.
But then you need to consider the added damage from an extra hit on DE, having 0 defensive abilities, etc. While DW doesn't help TP gain, it is a pretty big chunk to DPS, more than 6% haste.
80 Pup Brd, 75 War Rdm Drg Sam Mnk Pld Bst Thf Whm Nin Smn Blm Rng, 72 Drk, 63 Cor, 50 Blu, 40 Dnc Sch