Rune of the Nerubian Carapace
Assuming that it is usable on both weapons, this is a nice buff for DW tanks. Why they didn't just add 1-handed weapons to the original enchant, I have no clue...
One of these is more Parry than a single +2% (should be about +3% Parry). I don't know if two NC is greater than 1 NC and 1 Parry.
Either way, a buff to DW tanking.
Note: I think this really just covers additional damage from haste parrying. That means the only ways 2-hand should be superior to DW is in itemization and threat, which are kinda linked. And the difference isn't that large for casuals. Hit requirements are still a pain in the *** though.
[EDIT]
Fixed link.
Edited, Oct 2nd 2009 2:12pm by idiggory