Sony Entertainment Network president Tim Schaaf announced the move, but didn't add a lot of details to the mix. Schaaf said that he expects the iOS version to have feature parity with Android, which would mean streaming access to over 15 million songs, the ability to create playlists, and access to "Premium Channels" for premium subscribers. Premium subscribers will also be able to cache songs for offline play.
Sony is planning a single app to run on all iOS devices at first, with a native iPad app coming later. Sony's Music Unlimited service is definitely a very nice service, right up there with any streaming music option, and if you're a PS3 user, this may be a solid option.
source: The Verge