During an interview with Financial times Andrew House ( Sony Interactive President and CEO) confirmed the existence of the much rumored PlayStation Neo/4K.
“It is intended to sit alongside and complement the standard PS4,” -House
He also mentioned that Sony will be selling both through the life cycle and that the new model will target users who have 4K televisions, the Ps4K is not a replacement but will sit by the standard edition.
Much to our relief he mentioned one final thing.
“All games will support the standard PS4 and we anticipate all or a very large majority of games will also support the high-end PS4,”-Meaning, no compatibility problems between console versions.-NeoGaf