Oh I have to agree with this, that moment has been gloriously awesome.
That short-story was pretty necessary for explain Garrosh's character and motivations, not only because his suddenly "destroy the Alliance" stand showed in WotLK wouldn't had any sense, but because shows Garrosh as a well-motivated douchebag...but always a douchebag he was, and the beginning of The Shattering already showed that, despite his good points, something wasn't absolutely right about him.Read - http://us.battle.net/wow/en/game/lor...h-hellscream/1
Despite all of the problems with his story as a whole his short story was good and is definitely something you should read if you like Garrosh even a slither.
About this I think this article of WoWInsider is very well written and worth a read.
And also this, wrote by the same person that wrote the short-story, Sarah Pine. Beatifully written aswell.