Sony London have released some future plans for the Singstar franchise in a post on the official PlayStation Blog. Most notably Singstar is coming to PlayStation 4 this fall. It would appear as if it's coming via Singstar: Ultimate Party (a new compilation of songs that will see release both on PS3 and PS4). No word on whether the free-to-play app (available on PS3) will migrate to PS4 as well - Singstore will be there, but no word on whether your songs will transfer over cross platform.
Another big piece of news is that Sony will release a smart phone app that allows you to use your phone as a microphone when playing Singstar. While it removes a barrier to entry, we're not sure singing into a phone gives wannabe rockstar the same experience as a big ol' mic - but the option is welcome nevertheless.