Well I'm not a desktop Java developer anymore (thank the Gods) so I'll just take your word for it.
On a practical level, is there some example of a Java app which I could download and try out for native look and feel? See if my custom menu items show up, if I can drag a document window bar icon onto another application, basic stuff like that?
http://filthyrichclients.org/
Or willng to shell out money to frameworks like this,
http://www.jgoodies.com/