Another trip down memory lane, another unsub.
Maybe you are thinking of reactivating and giving this game a try. And I am not here to say that the game is bad, because truthfully I think pretty good. However, when you have been playing the same game and going through the same routine (like myself) for 7+ years, then it gets kind of old! Every once in a while, I get that "itch" to start up this phenomenon again only to realize one thing. Although the game can be fun, it continues to show its age. I keep hoping that the golden age of WoW will return but lets face it, that is well over with. The fact of the matter is that this game at its core remains completely unchanged. Kill X number of bad guys, collect X number of flashy items on the ground, grind rep, etc.
As far as raiding goes you have 1 of 2 options. Number 1 - Use the incredibly (and i stress incredibly) easy Raid Finder and see the content with zero challenge or Number 2 - Beat your head against the wall with plenty of wipes with normal/heroic. Not that normal is difficult, but you will wipe more than enough.
If you are considering coming back to WoW, all I can say is if you enjoyed the past 2 expansions then certainly give MoP a go. However if you are seeking the glory days of WoW with this new expansion, you will not find it. With plenty of F2P options out there that are honestly on par or better than WoW, it doesn't make sense anymore to pay $15 bucks a month for this. I can only foresee myself reactivating this again only if my friends do the same.