Stat weights are as follows relative to damage gained for 5.2
Not perfect yet, as simcraft has not yet put in the latest dk buffs.
Please keep in mind these stat weights use BiS gear, and the default simcraft profile, which includes the legendary meta. This means a changed race, talent, or gear, in particular trinkets and weapon, will change the stat values. I've seen far too many people trying to use these weights for characters that are 50 ilvls under BiS. I highly recommend running the sim with your own character to see stat weights for your character. Also, please note that, in reality, any time when you can't attack anything, or gain runic from AMS, the value of haste goes down a little for DW. Even though for some setups, haste will surpass mastery, it's still suggested to gear towards mastery for actual raiding as DW.
Stat
535 DW
535 2H
Strength 4.47 4.13
Yellow Hit 4.34 3.71
Expertise 4.77 3.94
Haste 2.23 2.50
Mastery 2.15 1.38
Crit 1.81 1.91
Hit Over Yellow 0.87 -
Weapon DPS 5.93 9.87
Offhand DPS 2.87 -