SingStar was announced for the PlayStation 4 earlier today. It is slated to arrive later this year and it will include a free SingStar app that will turn your phone into a microphone. That means you won't have to purchase separate or additional mics in order to play the game.
The app works with both PS3 and PS4 versions of SingStar and is compatible with most iOS and Android smartphones and devices. The app will also let you create your own personal playlists.

In addition to this, SingStar: Ultimate Party will be released on both the PS4 and PS4. It includes "30 epic tracks" and they will bring new news on that later on.

(via PlayStation Blog)