PSNow is not a world wide service. From what I believe PSNow runs off Gaikai which is only used in some parts of the world. From memory Gaikai cost Sony roughly $500m. Now if you put that into comparison with Azure, that cost MS $30b which is accessible world wide. Something I don't think Sony can afford unless they rent out Amazon or something. I will be curious to see how Nintendo and Sony imitate and implement this rumoured Xbox direction. Nintendo could possibly rent the servers out from MS and have there own access but I don't see Sony doing that as there relationship with MS isn't the same.
Sony can also rent out Azure.
If Microsoft succeeds in this endeavor, it will end up being fantastic advertisement for one of their most lucrative and fastest growing businesses.
Or SONY can work with Google, it's not like Microsoft who only have Cloud system around the world