Mainly to support fast switches of DPS with the pet if needed, you could use observer and stick it on the boss too for DPS. I don't like GoSAC because you barely cast any MG during the entire fight.Yo Sparko! Nice guide, I'd been messing around myself with stat weights lately, jo-jo'ing up and down on haste/mastery to see if there was some kind of breakpoint. This post saved me the trouble, and lots of gold. :p
Also, quick question, I noticed on your WF WotE kill that you were using the Fel Imp as Affliction. Any particular reasoning for that?