Salaam Remi spoke to Vibe a couple days ago and says that he's personally produced 2-3 albums worth of unreleased Nas material but Nas is notoriously finicky so he doubts any of it will ever get released.
At this point I'd rather a new album anyways. We're already getting the 20th anniversary Illmatic re-release I doubt that either Nas or Def Jam wants to spend too much of 2014 focusing on nostalgia when he's primed to drop new material.
And let's be real, all of us true Nas Stan's have at least 5-10 gigs worth of unreleased Nas material. Hell I've already got just about everything I could even dream of being on an official Lost Tapes 2 (sans White Man's Paper

) over the years from the unreleased Nas thread