Nentir Vale? I am surprised and not too much because I had forgotten it, but we have to admit that was possible because it is very useful as a "sandbox", a open world where lots of new things (for example PC races and classes) can be added. Maybe this setting can be used like a "nexus" between different worlds, like Planescape, Ravenloft or Spelljammer.
Later an oriental continent could be added with a reboot of the background of "Dragon Fist", and maybe also the return of the Jakandor island and the city of Ghostwalk.