This had been true of most larger businesses and academic institutes for quite a few years now as they all tend to use a domain server with centralised shared folders, with each student and teacher given their own access rights and storage space for their personal files and work. We used to have such a setup at university years ago.

But as you say, this is limited to access within the domain servers LAN so these files, resources and applications cannot be used from home or other off site locations. Also currently only select applications or utilities tend to be hosted on the central server and accessed from each PC or terminal, instead requiring most of the actual programs to be installed locally on each PC system.

The idea behind all of the ideas I mentioned above have been in practice for a long time, right back to the first main frames in fact as they used a central main frame linked to from terminals, so all files and applications were on a central system and the terminals just logged into and accessed the resources. This is the core of what is currently being pushed on the internet as Web 2. The browser is the local terminal, and the servers you access on the internet are the central main frame. So in fact we are finally going full circle back to the beginning. Central data and resource storing with remote terminal access. This does work well for the majority of computer based activities when implemented correctly, and so I wouldn't be surprised to see this coming true very soon with many applications being remote browser based applications that we run in our browsers instead of on our desktop.