Nobody knows either it will be good for Sony or Microsoft, because nobody able to predict the outcome for this project for the future. Would they have better deal with Microsoft instead with others ??? probably not. It's a not a long term plan. The deal can be change anytime. Also Cloud gaming need more than 30 years to become mainstream. Sony can still find more partner , it's just like using Taxi. You can use Uber or u can use other service. Sony not in the hurry or the one in need for the server.
I wouldn't say Cloud gaming needs another 30 years more, these companies want to push it now hence this megaton of a deal that was just made.
Anyway let us be grateful that too major companies are pushing hard to help push our industry forward.
The company can push as hard as they want but the reality is totally different . Infrastructure, government policy, politic , and other problem and conflict of Interest Stop the progression of technology and gaming. The Internet infrastructure is really bad and not in balance (The need of high speed internet are not equal to the progress of infrastructure, even in first world country).
Cloud gaming need, Speed, latency , Price and content. Even if all company joint together this problem will still exist. Also the console Industry are in the golden era, only on the losing side hate to see a console and local hardware device exist.
Cloud is the future, I am agree . But for now it's still premature and infancy. These company are preparing for the future but they are not in hurry. So I am glad they joint in hand for the benefit of both, gamer and world progress , but it need time.