Official CNN application for Windows Phone is live on the Marketplace. Of course, only Nokia-branded devices need apply at this point as they have an exclusive on the app for a few months.
The application is really well done, in the classic style of Windows Phone Metro and with a clear and elegant display of the content. Do not miss the functionality of push notifications with LiveTile to indicate some possible 'Breaking News'.
CNN is a free app an can be download from the WP Marketplace exclusively for the Nokia Lumia phones