Seriously, UNIX guys have had this for decades. Ever heard of keeping your user directory and profile on the network server. So when you walk around the office and log into different machines your HOME "travels" with you.
The network server now just lives on a server outside your organization/home what ever. The network speed now becomes the biggest limitation, and there are valid concerns with security as well.
I'm perfectly aware of that. I use OS X as my primary OS. My point is that who ever is saying that iCloud is all about killing Windows is missing the point completely, first because the technology not that new or amazing, and second if it does anything to Windows user base it's doing it indirectly and not as some planned consequence.
The network server now just lives on a server outside your organization/home what ever. The network speed now becomes the biggest limitation, and there are valid concerns with security as well.