I've gotten JMEDesktopPane to work, in that it's showing up where I want it and displaying the window/s I want.
However, I can't make it display any L&F other than the plain Windows L&F. I'm using JRE 6 update 3 (or whatever the latest is – got it two days ago) with the 1.0 release of jME (jars, not source), and building using Eclipse 6.0 (which shouldn't matter).
GameSettings gs = new PreferencesGameSettings(Preferences.userRoot());
Later, I create the desktop (actually, multiple desktops, only one of which is visible at a time) and a JInternalFrame on it. That JInternalFrame shows up with Windows decoration, not Motif. I've also tried requesting the Metal L&F with no success.
While I understand that, the truth of the matter is that someone looking to start using JMEDesktop, and not getting the LnF he's expecting, will first look at the documentation for JMEDesktop. Even thinking to search for the PropertyDialog or AbstractGame classes for Swing-related stuff doesn't come obvious at all. According to the principle of the least surprise, the right place to start documenting it (or at least put an obvious pointer) would be in JMEDesktop. (I'm not against also putting docs in other places).
Of course, I don't use CVS, so I might as well wish for a pony while I'm at it