Read original post by Dare Obasanjo at Windows 8 App Developer Blog
Thanks to the cloud, Windows 8 customers can work and play seamlessly across devices. By signing in to your PC or device with a Microsoft account and taking advantage of free personal storage in SkyDrive (see Connecting your apps, files, PCs and devices to the cloud with SkyDrive and Windows 8 for more info), your apps, settings and personal files are always with you. As an app developer, you can take advantage of these cloud capabilities by integrating with the Live SDK in their Metro style apps.