David is taking virtualization well beyond the data center, extending it on the desktop and applications. Essentially the whole software stack is virtualized, but not in one OS instance, rather it's at each level of software. Applications don't install themselves into the OS, they are virtualized and streamed in real time to the desktop. Even though the app may think it is installed into the OS, it really isn't - that installation has been virtualized. Two keys to doing this is; 1) identity, 2) policy based management, e.g., Active Directory. For your apps and data to follow you, both have to be in place in order for you to migrate between virtual desktops, and operating systems. David also stressed managing both the physical world (servers/machines) and the virtual world from one pane of glass. That's obvious since he's part of the Microsoft System Center product group.
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