Review: Samsung Focus 2 for AT&T
The Zune Music Store and media player are the default clients on any Windows Phone for consuming music and video content. The Zune store can be used to purchase content as well as serve as a source of info for the content you've sideloaded yourself. It relies heavily on the Metro UI concept and requires a lot of swiping back and forth to successfully navigate.
The music and video playback tools are decent and work with DRM-free stuff. If you've got any content that has DRM attached (like movies downloaded from iTunes), it won't work.
You can hit up the Marketplace to download other music apps/services, such as Slacker, Vevo, and Pandora. Once you do, they'll be recognized by the Zune software and added as options in the Zune Hub. That means you can access all your media from one place, rather than digging through the app menu to find all the different music apps.
Music sounded great through my favorite headphones, and HD video content looked nice on the Focus's display.
The only AT&T-branded media app on board is its U-Verse Mobile app. This app lets subscribers of AT&T's home service access and use some of the features of the home DVR, and so on.