I was just watching videos about Sha on youtube, started listening to all the voices of the Sha, people were commonly making jokes about them sounding like old Bosses...but then some one pointed out something about the Sha of Violence.
"I will return...Caged....Voice of Illidan....This is very very exiting, Illidan is going to return in MoP by my theory because the sha can take control over anyone, Illidan was a hero but put down by his people, then after his entrapment he came out for revenge and he is mad and back in action to take over."
I know that Blizzard reuses voice actors very often, but it is something interesting to think about.
Lets say that Sha of Violence is the spirit of Illidan for some off reason.( Long stretch that it is.)
Who are the other Shas?
Compare his voice to this, especially the last part.