I think taking this sort of context snapshot may be very difficult. If you assume no direct application integration. It would almost be like you would need a mechanism to operate in a partition of RAM where it could not interact with the current running context but stream all of the RAM in use to disk.

Also it'd would be a data integrity nightmare because if one context shared the apps from another. How would you manage memory corruption, and allocation and saving in this sort of scenario.

Anyway, sounds awesome.

Good luck