Personally, I want the opposite of "settings and files ... accessible in every context"—I don't want my personal data or configuration touching a corporate network, or vice-versa. I want the "bring your own machine" philosophy to be taken to its fullest extent: where there's no such thing as a workstation any more, because everyone just owns a PC (their phone) that they bring to work, which maybe contains a sandbox/VM with their work stuff in it, or acts as a thin client for a corporate shell-server, but is ultimately their machine.

This enables you to e.g. set up your own VPN for host traffic, to securely access whatever you want during work hours, completely opaquely to packet-sniffing on the corporate network. The "work sandbox" can ignore that VPN and just use the corporate network (maybe through its own VPN) like normal. Whereas with a shared workstation + LAN, all your personal data and traffic and ability-to-use-software is completely at the behest of corporate IT policies.

Oddly enough, this is already pretty much what the experience is like for iOS with a MaaS360-managed profile installed and Exchange ActiveSync-based accounts set up. Translate that to a desktop UI while keeping the isolation metaphor and it'd be perfect.