WOA will include Metro-style apps, including Microsoft specific programs (mail, calendars, contacts, photos and storage), which will be bundled with WOA and Windows 8 on Intel, in addition to support for IE10. We think this is a positive in that it will enhance the app ecosystem at the time of launch and competitor Apple does this as well.
In addition, WOA will support the desktop mode. It had been speculated that this would be cut for the Windows on ARM version of the OS. This enables users to have the option of the old interface or to select the new Metro interface to their PC. Microsoft has found a way to have this option without degrading system performance or battery life.