In a blog post Microsoft announced that the next version of Windows operating system, Windows 8, will support USB 3 devices. USB 3.0 devices support data transfers at 10x compared to today’s widely used USB 2.0 devices.
In simple words if copying of a HD movie to your USB today takes around 15 minutes then in Windows 8 the same movie can be copied in 80 seconds to an USB 3.0 device.
Fore more details of technical implementation of how USB 3.0 support is implemented in Windows 8 read this blog post also there is a video demo at the bottom of the blog post.