Varian has been waiting to kill him since Wotlk. Plus Garrosh has tried to kill his son, Anduin. Jaina hates him for destroying her home town. Vol'jin wants him dead for trying to get him assassinated. Lor'themar wants him dead for abusing the Blood Elves.
And then there's Sylvannas who didn't appreciate being called a bitch while being told what to do (which also got her killed in the process). Saurfang would like to teach him a lesson for being a huge dick.
I'm pretty sure Thrall wants to "ground" him.
Then there's the Tharan-Zu and his Pandaren who hate him for destroying the Vale.
Darion Mograine gonna fly on a borrowed Val'kyr slice him in half and raise him as two Death Knights: Upper Garosh and Lower Garosh. He can also fuse Upper Garosh with corpse of onyxia and Lower Garosh with pixie dust left from Deathwing crating ultimate villain for next expansion (or maybe two).
There was a B-movie about Assassins competing with each other in a race to kill someone for a prize, but all of them get screwed over in the end (the guy they tried to kill set up the whole thing, and he was finally gunned down in his car by one of the agents who was duped into protecting him).
That movie is what Garrosh's situation reminds me of. He's probably got more than 5 people going after him (Wrynn, Chen, Vol'Jin, Sylvana, Thrall, etc.).
I'd love it if there were like cliché flashbacks to Vol'jin and Saurfang's speech, + that Varian and Thrall-rage, and after they're all done, Garrosh falls to the ground, and the last you see (through his eyes) is Vol'jin charging an arrow, and Saurfang and Varian, and Thrall walking towards him. But we don't actually see the kill, meanwhile we see Lor'themar and Baine n shit fighting outside, winning. And then they just stand there waiting. Then the other guys come back like "duh tha war be over" and everybodies not like "YEAAAH " but "hm." and leave ORgrimmar
I'd like for it to be Sylvanas and the Forsaken, I would at least hope that she were present so as to gloat over the fact that, in Silverpine Forest, Garrosh issued a veiled threat that it was in fact her death that was impending.
I do however think it will be Vol'jin for the Horde, and Jaina for the Alliance.
I'm not sure how it would work having different NPC's for different factions, and then blizzard chosing one to be canon... In Cata thrall was neutral. My guess is that it will be someone neutral this time as well. So a panda, thrall or vol'jin - with vol'jin having slightly different post killing dialogues for each faction.
The Argent Squire. We have saved the world again and again, only to be treated as unknown noobs by both complete strangers and groups associated with multiple factions that we've already done rep grinds for (and we learn to fly every time we see something new too). We will have Garrosh about to fall, his final enrage timer will be about to pop, the heroes of lore will be exhausted, tattered lumps on the floor ... and the Argent Squire will step in to show us that we're just spear carriers in the story. He will one shot Garrosh and the next expansion will begin with a pug treating our left boot as a fire hydrant. We will then grind faction rep with the Sweepers, a mysterious group of broom wielding mystics who keep talking about Rule #1 while keeping the cities of Azeroth sparkling.
[I like WoW, but there are times I find certain patterns painfully predictable.]
Griftah for Warchief! We'll never fear Tikbalang again!