Leaving aside the fact that the cloud, as it is currently set up, gives me a bit of a bad feeling, I think integrating everything into the browser with open standards (like HTML5 (excluding the unfortunate but necessary h264) or WebRTC) is the best way to make services accessible and have the same quality on all operating systems. It is also a way to be able to choose a "client" trusting that it will always work.
In terms of communications, the fact that the client is in the cloud or installed on your PC is of little importance: whatever the form, the data flow will end up going through a central server and no matter if the client is on your PC, if the service fails, the client is useless.
As for toy computers and operating systems, they are just that: a toy.