Diablo 3 is coming to both current and next-gen, but you'll have to wait a little while to play on your PlayStation 4. The PS4 version will arrive in 2014, not alongside the current-gen versions this year.
According to notes from a recent interview on DiabloFans (via Polygon), the longer development time for the PlayStation 4 versions will let them tailor it to the system's specs, rather than merely porting the current-gen versions. The PlayStation 3 and Xbox 360 versions are still coming in September, as previously announced.
If you want to get your hands on the game yourself, you can head to the San Diego Comic-Con this week. The current-gen versions will be playable at the event.