I know a games dev who works with sony and they are being told that ANY ps4 game will be required to fully work on the normal ps4, with the neo being able to provide better FPS,resolution or graphics enhancements such as you would find on a pc game. No "exclusive" neo content or neo "only".
He said this is cast in stone and is a requirement of publishing on the playstation platform.
So seems that they are keeping a tight control on things.
I've seen some shoddy games for the PS3 that works but doesn't perform well.