BEWARE: The used rotation is not for maximizing Dps but for convenience and fun aka farming/bg/lowleveling! The reason behind this is best explained by griemak over at shadowpriest.com.
"There is no rotation. THERE IS NO ROTATION to Shadow Priest in regards to maximizing DPS. A set rotation is used for trading DPS for convenience, otherwise known as "facerolling" (much better results if you are another class, facerolling as an spriest is not a great idea)."