Java has matured in terms of UI presentation.
search project Aerith for examples on some of the neat things that can be done when mixing JOGL, Swing and Java2d.
However, it seems these only work on windows. Mac is still strangely alienated from the Java revolution, cuz Steve still strangely insists that his boys be the ones to create their own JVM perhaps? These UI improvements have been around since 2006 and here we are now in 2009, with "Java for Mac (java 6)" not having JOGL/Java2D interoperability support.
Has anyone tried playing around with JOGL on OSX? Did you try running the XTrans demo on the JOGL site? Did it work for you?
Even trying to compile the source code for the Xtrans demo gives me this:
Error: XTDesktopPane requires new Java2D/JOGL support in Java SE 6