PS Now is the streaming Sony’s service for an ample set of devices, obviously PS4 will benefit of that service. According rumors, Sony could offer to rent videogames in PS Now and those titles would be played through the internet, you won’t download it, you just would play it using an internet connection.
PS Now could reach PS4 shortly regarding this picture captured by a Reddit user:
Sony would be prepping PS4 for their upcoming streaming service. Those games showed in the picture can’t be downloaded; you just can check rates and trailers. I guess Sony will give price and specific details for PS Now at E3 14.