There are 2 flavors, one of them is for spammable without being behind the target and the other one is for behind the target D’oh!
Version 1 - This one is for brainless smashing button from any position around the target
/castsequence [stance:3]Ambush;[mod]Redirect;reset=target Hemorrhage,Slice and Dice,Hemorrhage,Hemorrhage,Rupture,Hemorrhage,Hemorrhage,Eviscerate
/castsequence [combat]reset=60 Shadow Dance,Shadowstep,Premeditation
/cast Shadow Blades
/startattack
Version 2 - This one also uses Ambush when Shadow Dance is up, but is only usable when behind the target because of the Backstab rotation, also hold any modifier key for Redirect:
/castsequence [stance:3]Ambush;[mod]Redirect;reset=target Hemorrhage,Slice and Dice,Backstab,Backstab,Rupture,Backstab,Backstab,Eviscerate
/castsequence [combat]reset=60 Shadow Dance,Shadowstep,Premeditation
/cast Shadow Blades
/startattack
These macros can be easily transformed into PvE or PvP by simply edit/changing these words: Recuperate to Eviscerate or viceversa.