REPLIES 
It can be Stealth for using Ambush/Cheapshot,
or it can be Vanish for getting out of combat, for doing anything that require being out of combat (eating, refreshing potion CD, etc...).
Or it can be Shadowstep like you said, because rogues are too damn lazy for walking behind a tagged monsters...
REPLY
Lavatherm
and the rogue goes "Poof" shadow step i presume...