Imo the best rotation atm is Devouring Plague, Shadow Word: Pain+Inner focus, Vamp Touch and then spam Mind Flay. General rule is to NOT clip your dots. As far as I have been testing, swp seems to be reactive spell, which means that u shouldn't wait for 5 stacks of shadow weaving or to recast it on trinket procs. When a trinket/ring/cape or whatever sp proc occurs, swp increases its dmg for the duration of that proc. On the other hand, swp+inner focus seems to give alot more crits, again as far as I have been testing this. Another thing is if you CAN cast VT before the boss pull( so the actual cast time from the moment of pulling will be like 0.2-0.4 sec.) it is better than dp+swp. If you dont know when the tank's gonna pull the boss, DP+SWP seems alot better, because u wont lose 1sec casting time without doing ANY damage. That's from a PvE point of view. For PvP it's better to start with VT+Mind blast, then DP+SWP and spam mind flays.