The operating system designed for these users will be a very simple one. It will exclude features that many think of being the main components of an operating system today. The next generation operation system will
- not have a complex window manager
- not expose a file system to the end user
- not expose complex OS settings and configuration
- store user data in the cloud, instead of in a local data store
- run applications on the cloud or as web applications, instead of on the local CPU
This may sound like SciFi to many at first. But if you look close, you will see that major players are already competing in being the first to deliver this kind of operating system to the end user. Apple builds the iPad which has a very simplified operating system. Google builds the Chrome OS, which is supposed to be a cloud OS.
Rumor says that internal discussions at Microsoft regarding developing such operating systems got blocked because such operating systems do not fit well with MS Office. I would predict that it will not take long until they change their minds.
Current operating systems will not disappear completely, of course. They will still have their purposes as servers, workstations or as gaming platforms (the later will not last long, I would say). It may also be that end users will still own an ordinary computer with ordinary operating systems for some time. But for every such computer the users will own at least 1 or 2 devices which will be running the new next generation operating systems.