"JSR-296 (Swing Application Framework) is no longer developed and will not become part of the offical Java Development Kit as was originally planned. You can still use the Swing Application Framework library as it is, but no further development is expected."
So... What to do? New API replacing it?
The swing application framework was a project to create an application framework on top of the swing GUI widget library. IIRC It had some of the same functionality that http://swinglabs.org/ has. It was intended that future versions of Java would ship with it.
It is not the same thing as the swing GUI widget library which already ships with Java.
More details on the difference between an application framework and the GUI widget library can been found in this interview with the lead for the JSR.