Originally Posted by
AbalDarkwind
There's, at least, four ideas for expansions left: Azshara/N'Zoth, Return of the Lich King, another Faction War, and the Void.
Azshara/N'Zoth will be in the South Seas. There's plenty there for, at least, one expansion.
The Return of the Lich King is inevitable. Many will see it as a rehash, but if they combine it with the underground areas of Azj'aqir and have the Lich King resurrect the entire Black Empire, it'd fill out an expansion fairly easily.
There's going to be another expansion about the Faction War. Maybe they'll pull out the fabled "Other Side of Azeroth" as a setting, or maybe it'll just be a max level revamp of the Old World. Combine it with maybe Xal'atath controlling a Faction Leader and doing what Y'Shaarj couldn't, fully resurrecting, and you have another expansion.
Finally, we have the Void. Alone, it's likely boring, but combine it with the remnants of K'aresh and maybe the second Draenor continent (Maybe K'aresh IS the other Draenor continent and wasn't an entire world after all! Their "Second Sun" could have been a Naaru or something else more mysterious; depends what Blizzard wants to do with these two locations), and have Dimensius as the main villain. There's another expansion.
Finally, and this one is a bit of a stretch, we could go to Azeroth's moons and have a Cosmic expansion where we learn the origins of Elune and perhaps even the mysterious Crooked Serpent with No Eyes. This could be interesting as the final WoW expansion where we destroy the Void Lords and maybe even Sargeras once and for all.
There's plenty of lore left without resorting to just pulling lore out of thin air. The only bit of lore that'd be "new" that I mentioned above would be any continents and cultures on the "Other Side" of Azeroth. However, but I feel Blizzard could get away doing this one more time, like with Pandaria, especially if they have an interesting idea for the cultures of said region and, perhaps, tie it in to the little-known fifth Old God (AKA Xal'atath) and the birth of Azeroth as a Titan.
So, four or five more expansions is 8 or 10 more years of content. That's quite a bit for them to play with.