I'm throwing this out there just for fun. Nothing too profound.
But his albums tended to be in pairs.
Slim Shady LP - Putting on a light-hearted persona for the public
Marshall Mathers LP - Darker, drawing a distinction between his persona and his real self
Eminem Show - An introspective display of his life, at times angry and intense
Encore - abandons controversy for fun, but overall a more natural calm laid back view of his life
Relapse - his descent into bad habits (a return of his dark persona)
Recovery - a personal transformation (a showing of his real self)
Basically, each sequel is a more mature perspective of who he really is. I do think Encore is a more mature version of TES (even if it has tracks like Rain Man), but that's another topic of debate.
So I suspect that his new album could be a sequel to Infinite. Full circle.
Or, if it's a completely new concept, the album after that will likely be a sequel to this year's.