I know this could be covered in the audio leak thread, but I figured it might be worth separating.
So, holy shit. For those not aware, Y'Shaarj references two things previously mentioned (quite ominously) by the Puzzle Box of Yogg-Saron: the "dark forest" and Ny'alotha.
"You will rest in Ny'alotha..." - Y'Shaarj
"In the land of Ny'alotha there is only sleep...
In the sleeping city of Ny'alotha walk only mad things.
Ny'alotha is a city of old, terrible, unnumbered crimes..." - Puzzle Box
The mentions of the "dark forest" are much more cryptic (if such a thing is possible), and I don't find them as intriguing, but you can seek 'em out if you're interested.
So is the Ny'alotha talk just two opinions on the quality of a bed in breakfest? Or perhaps, could it be the mysterious origin place of the Old Gods? The latter is interesting, but rather hard to believe. Harbinger Skyriss seems to claim that "they" are as "countless as the stars". If we are to believe he is referring to the Old Gods, well...it makes their place of origin all the more formidable.
It's possible that Ny'alotha is an Old God "city", or at least a stronghold of some kind. Perhaps that is where they are imprisoned, and perhaps it is the place they retreat to once they are "destroyed". We know for almost certain killing the Old Gods is impossible, or very nearly so. Y'Shaarj himself is evidence of this, as he was partially resurrected by Garrosh's forces, despite supposedly being slain by the Titans themselves. As well, Yogg-Saron speaks to players from beyond the "grave" through the Puzzle Box, and C'thun has shown a number of signs of a possible return, including quests in the revamped Silithus that had involved his presence and even his Eye, but were ultimately left out of the game.
Come on, lads. Lets us have a good ol' lore discussion.