I think everyone in the thread forgets about one, crucial thing - XBL and PSN. Sony might base their streaming service on a rented platform, even MS Azure as someone already mentioned, but everything will have to be streamed through PSN nevertheless, as you will have to be logged into Sony platform to play the games, and we all know how terrible its bandwidth is, the "slow PSN download speed" threads pop up basically every single week all over the gaming forums, there are hundreads of tricks on YT how to speed up the internet connection on PS3/PS4, and even they work only for a very narrow amount of users. XBL on the other hand, since that one patch where they make some sort of wizardy, works pretty much the same way internet on PC does - you just plug in the cable and anjoy the full speed of your connection, without even going to the settings menu. Even the wifi, with XB1 using weak antenas, works way better than the cable on PS3/PS4.
And then you have moments when PSN isn't available at all, how on earth they want to go into streaming games with such a critical issue in the first place? Back in the PS3 era they had excuse, "hey, it's bad but at least it's free", but since PS4 and forced paid online, one would think at least some of those money will go into upgrading their infrastructure to remove the bandwidth and out of service issues, but nooo, Sony prefers to put all the money into their own pocket. And this will be one of the many acts of arrogance of this gen that might pay them back in the upcoming generation.