From ZDNet in reference to Windows 8 ENTERPRISE (only):
Windows To Go
Windows 8 Enterprise also includes the tools needed to make a Windows To Go USB drive. A fully-managed portable version of Windows, Windows To Go uses standard Windows image files to create a bootable version of Windows 8 â€" so if you're allowing your users to use Windows To Go, you'll need to create the appropriate image files and make them available for use. Users will also need USB 3.0 drives (which work in USB 2.0 ports), as these have faster flash memory chips with better random access performance than USB 2.0 drives. We'd also recommend using a drive with at least 32GB of space.
More information on this awesome new feature (something present in linux for years) is here: http://en.wikipedia.org/wiki/Windows_To_Go
Firs time I've seen this yet. Is this really possible? I mean making Windows 8 portable?
Yup, just it need a Internet connected computer and a supported network card.
So it can get the driver that don't contain in the USB drive.
And some windows 8 user also testing it by bring it to the cyber cafe. ;)
Like a virtual machine without needing a host machine ;). Just make sure the PC you try it on at *least* was made for Vista or above, with Windows 8 or above preferred.