Recent development version of NetBeans 6.7 has better look and feel on OSX. But if you take a look more closely, you will find it is still far away from what should be actually done.
I've tried myself to play with it. Again, Swing by architecture outperforms SWT, that is still (and probably forever) is using Carbon, instead Cocoa. But that's very bad news to those, who is using it: Carbon probably gone in Snow Leopard. Swing, on the other hand, has a destiny to be permanently fake maker, drawing everything by itself.
Well, anyway. Focused and passive window looks like this for me in Java 5 and Java 6 for Leopard — notice also a scrollbar... :-)
Cool? No! I am actually very disappointed by... Apple. They're completely screwed Java 6 made it even worse than Java 5 (maybe because Java 6 was entirely handled by Apple?). Apple should push Java in front as a flagship product, but they're stick to Objective C, unfortunately (who the hell needs it on OpenBSD, for example?).
On one hand, the future of Java on Apple (and not only), however, is not that much dark anymore: it is at least open source (kudos to Sun). On the other hand, knowing how open source bazaar applies to projects — that's why X11 still sucks on desktops big time, no matter what you use there: KDE or GNOME (GUI No One Might Enjoy)...
Will see and contribute, right? :-)