In my opinion it is absolutely clear, that N'Zoth's prison will be uncovered by the raise of Thal'Dranath.
I'm absolutely aware that other threads had handled this topic already.
But I'm absolutely certain that Nzoth will be in connection with Thal'Dranath.
Look at these two maps,
http://wowwiki.wikia.com/wiki/N'Zoth...or-Ordered.jpg
http://wowwiki.wikia.com/wiki/N'Zoth...leLocation.png
Why else should they create this potential geographical connectivity? In chronicle it says that he's enchambered in an enchanted prison below suramar, through tectonical activity shifted south to future Thal'Dranath.
Adding to that, it's absolutely clear that blizz emphasizes with wotlk this time and an old God as enemy of an expansion would be the perfect try. and the old God cycle of cthun, yogg, yshaarj and now Nzoth would fit into a plan maybe made years ago with an old God every two xpacs.
This is pure speculation but I think it's well fed with the geographical connection.