Some things will - as they are today - be stored in the cloud [edit or its local equivalent using WCF]. While bookmarks may be one of them - many of the items I bookmark when I'm actually working on a project rather than procrastinating on HN et al., are pretty project specific. And of course, having HN et al. in its own virtual machine would allow all those idea bookmarks to be stored in one place relevant to their useful context rather than relevant to a file system which I have to keep organized (assuming I bother with organization).
Most people don't keep their filing system very organized and when it comes to bookmarks even less so. Context is often a more efficient way of recalling what you did than a directory name - particularly over longer periods of time such as several months.
And of course, you can multitask across virtual machines - I often have two or three open at once because I need access to software which runs on a legacy version of Windows and I run Facebook in it's own exclusive VM.
At the same time I will be working on a project on the host OS. And there is no need for interconnection between any of them.
And VM's solve a lot of legacy issues, cross platform compatibility issues (e.g. windows phone apps) and Microsoft has already developed methods of integrating VM's with the host (see Windows Virtual PC and XP mode integration).
I don't disagree. But as we move to a world with more virtualized environments and multiple devices, I think it will be more common. At the very least iCloud will make it standard in the iOS/OSX space. I can't help but believe MS will do the same for Win8.
we are talking VM's... not multiboot. you can have many VMs(applications) open at once time. those application have access to the shared disk and other resources. have you seen parallels? the user would not change workflow _at all_. they dont know their app is now in a VM.
Again, saved state. In my work projects often go on hold for months or years - I might need to come back to a project and pick up where I left off even though in the interim I replaced my primary computer, browser, and production software.
And in my writing side projects, I may leave a project for several months. So that's where I realized the value of VM's - the one's I use have survived an upgrade from XP to 7 with the same open windows and without any software reinstallation (and of course without any recreation of bookmarks). I'll add that they are also descendents of previous virtual machines used for the same purpose but different projects. It is more efficient from a workflow perspective to have six copies of Open Office each pointing to the relevant context than to reconfigure one copy each time the context switches.
To put it another way, the way in which one develops software projects from a custom starting point and the way in which references persist across IDE sessions during a project due to saved state are not unique to software development. They are indicators of the features which facilitate efficient project execution timelines.