There is some progress towards an internet operating system, by which I mean a highly standardised set of protocols for single-sign-on internet access to a virtual private network (VPN) of all our files and machines. There are several companies in position to start offering this, and they're all taking different approaches, if they're thinking about it at all. Microsoft's solution would grow straight out of Live Mesh, Canonical would use Ubuntu One, Google has a mishmash of data services that could suffice, and Apple of course has MobileMe with the bonus (for them) of tyrannical control of hardware too. And unless any of these services are built on open standards (unadorned by proprietary "enhancements") then any one of them winning would be bad for everyone. The ones most likely to build an open platform are probably Canonical and Google, though I wouldn't bet on either of them.
What I'm thinking of here is the reverse of the old workgroup structure. Traditionally, the "workgroup" or "homegroup" on Windows has corresponded to a LAN subnet, or a way of segregating locally-connected machines into groups that cannot talk to each other. What we need to start enabling is for people to join groups that span across LANs and the internet so that joining a workgroup from anywhere means being connected to those machines too. In other words, leave the subnet concept behind and start to think of VPNs instead. "My Computers" should be accessible to me from wherever I am, at work or at home, visiting family or on the road.
Mokalus of Borg
PS - These companies can offer the central sign-in authority for your VPN.
PPS - All except Google would probably be platform-specific.