One of the more interesting features that is suppose to show up in Windows 8 is something called Direct Experience Mode. The general idea behind the feature is the idea that you could take a DVD and insert it into a drive before booting your laptop and instead of booting into the operating system the laptop would load a media player to play the DVD.
Now according to the Windows 8 News blog Microsoft applied for a patent back in January under the title of: FAST BOOTING A COMPUTING DEVICE TO A SPECIALIZED EXPERIENCE. As the post points out this patent describes a boot process that would load a virtual machine manager which would decide which general or specific purpose operating system module would get loaded.
Described is a technology by which independent computing functions such as corresponding to separate operating systems may be partitioned into coexisting partitions. A virtual machine manager, or hypervisor, manages the input and output of each partition to operate computer system hardware. One partition may correspond to a special purpose operating system that quickly boots, such as to provide appliance-like behavior, while another partition may correspond to a general purpose operating system that may load while the special purpose operating system is already running. The computer system that contains the partitions may transition functionality and devices from one operating system to the other. The virtual machine manager controls which computer hardware devices are capable of being utilized by which partition at any given time, and may also facilitate inter-partition communication.
Long Zheng over at istartedsomething.com suggests that this idea would also be incorporated with Microsoft’s Hyper-V technology.
UPDATE: it appears that the originally information for the post on Windows 8 News regarding this was originally posted on Being Manan where there is also some additional info. My apologies to @manan for missing this and many thanks for letting me know on Twitter.