Windows To Go
After experiencing it first hand, I can only say that Windows To Go feels like magic. The potential uses are truly overwhelming. Read on to learn why.
Windows To Go allows you to capture a fully configured Windows environment on a USB stick and use it to boot on any host. This is not just booting Windows from USB – which was theoretically possible before – this is about specializing the image for each host you boot from it. It’s about taking your operating system on the go.

Some of the enterprise scenarios this enables are downright incredible. Think about a corporate employee being able to take home his work system and pick up exactly where he started. Imagine a police officer booting the police car PC off a personalized Windows USB stick. Consider a software consultant who doesn’t have to bring in his laptop to the client or to a classroom or to a shared machine.
Consider also the consumer scenarios. You could come into an Internet café with “your own Windows” and leave no trace of your activity on the shared host. You could come over to your parents over the weekend carrying only a USB stick.
Windows To Go works off standard USB sticks, and can support USB 2.0 and USB 3.0 drives. During first boot on any system, the image from the stick is specialized for the specific hardware – and then remembered for future use. (This specialization process took just under 2 minutes on my MacBook Air.)
Another awesome feature is what happens when the boot drive is surprise-removed, say yanked out when you accidentally misplace your laptop. When this happens, the kernel freezes the display and you have 60 seconds to plug the drive back in. After you do that, you can continue working normally. (I wish the screen could read something like “Boot drive disconnected. You should reconnect it immediately.” – but it is apparently very difficult to implement.)
Surprise removal and reconnection of Windows 8 To Go USB stick from MacBook Air
As you may have guessed, everyone who attended Steve Silberberg’s session on Windows To Go got a Kingston USB 3.0 32GB drive with Windows 8 To Go:

Ten minutes later it was plugged into my MacBook Air and “specializing” for its hardware. Alex was so kind to video this for me:
MacBook Air booting from Windows 8 To Go USB stick
Fifteen minutes later I was logged onto Windows 8 with my Live ID and enjoying all the settings (including my login tile picture!) I configured previously on my Samsung tablet.
This is one of these unique experiences with a computing technology that leaves you with your mouth gaped. This is magic.