Sony has been very coy about their upcoming PS Now, their cloud based game streaming solution powered by Gaikai, that will allow us to play PlayStation games even on non native hardware (one perk of this being backwards compatibility over the cloud). It makes sense that they have, though- PS Now is a massively ambitious undertaking, and relying on the cloud to play games probably comes with its fair share of problems, problems that Sony simply does not want publicized, at least not now, when they are still in the testing stage.
These are problems, however, that have been highlighted by this leaked video that shows us the PS Now beta- it shows us what the UI looks like, it shows us the kind of lag we might expect (the user who uploaded this has a 100mbps connection, and he still gets a warning about his connection not being good enough, suffers from 50 second long loading times, and massive lag during gameplay), and it shows us how games are rented, and how PS Now integrates with the PS4 OS.
It seems like there are a lot of problems with the entire setup right now- it simply does not sound like a feasible way to play games. Of course, PS Now is still in its very early beta stages, so things might improve, but there’s only so much that improvements to a fundamentally flawed idea can do.