Unity has announced that with Unity 4.3 they are releasing Unity for PlayStation Vita to the public.
Developers with a licensed developer agreement from SCE for 
PS Vita will now be able to deploy their game to PS Vita via the Unity engine and make use of platform-specific functionality including:
· Motion sensors
· Front and rear cameras
· Dual analog sticks
· Rear Touch pad
Furthermore, Unity for PS Vita will allow them to integrate the full suite of PSN features into their games, including Trophies, Friends and Matching functionality into your game. .
Unity for PS Vita allows developers to develop their game once, without rewriting the code from scratch; simply build and run it on the PS Vita devkit. Not only that, developers can now create both 2D and 3D games with Unity 4.3, animate almost anything with the native animation system Mecanim, and implement awesome graphics.