The Unity for Tizen Beta program has been updated to work with the recently released Tizen 2.3 SDK and Unity 5.0 and is open to developers to join. Developers can test their Unity games and report bugs in the bug reporter, join the google forum group to discuss and ask questions about new beta features.
Registered beta users will be provided with a trial license that will unlock the Tizen functionality in the Unity game development environment. Samsung has recently announced support for the Unity Game Engine in its Tizen TVs.
You can apply to Join the beta group now by filling out this Online form.
Here is a quick video showing SHADOWGUN running on the Tizen RD-PQ Developer device at the Tizen Developer Conference 2013.