"All Windows Phone 7 updates, including carrier updates, will be distributed through the Microsoft update system. Updates will be disseminated OTA or through the Zune Software installed on a PC.
Windows Phone 7 is tightly integrated with Windows Live ID in a manner similar to Gmail is to Android and iTunes is to iPhone OS. A Windows Live ID is the gateway to the Marketplace which just so happens to be the only place one can go to get applications (side-loading is not supported). The Windows Live ID must be entered in order to use the phone and is required for data synchronization to and from Microsoft’s servers. The device must also have a Genuine Windows Phone Certificate which is necessary to authenticate the device."
