I deeply wish for another grand epic questline not connected to legendaries, much as I wish for another incredible world event. It's things like this that make me regret being a cata baby, even though I know I've enjoyed the game more this way. It's kind of sad, because it makes me feel like the greatest things to be done in WoW have already passed; the best we could do is gone. No matter how incredible the slaying of elemental lords and Old Gods is, they're just bosses.

Wouldn't it make sense for there to be world bosses again in some fashion? The Whale Shark is sort of the best form of that- no loot, only the fun of the kill. Imagine, an Old God rises from the earth, more powerful than any that came before, and it keeps coming back. For it to be beaten, the entire server has to fight against it; low-level players taking on the outlying tentacles, and as you go in they become more powerful, until at the center it's a race to defeat the beast's central body. It could become more powerful for each part of its body remaining, with a buff that stacks for each tentacle, floating eye, etc., so that it can't be beaten if the respawns aren't constantly being taken care of.

Just a ramble that occurred to me, but with all the Old God buildup we've seen, it makes sense.