Microsoft has purchased a number of Xbox related domain names recently, including XboxPhone.com, XboxTablet.com, XboxLiveTV.com and XboxCompanion.com. Two however rang a particular bell.
Microsoft also purchased Xbox8.us and Xbox8.org, which of course connects very well with the Windows 8 and Windows Phone 8 brand names which will be marketed heavily in 2013.
This of course makes the name very likely, which means we can safely move on to speculating about the XboxPhone 😉