Matisse GroupLayout has been integrated into Mustang at b76!
I heard a piece of news from NetBeans community that the GroupLayout is bundled into the JDK build 76. Please search for "Add GroupLayout to core" (bug #6375459 at java.sun.com):
https://mustang.dev.java.net/files/documents/2817/31069/mustang-b76.html
To me, this is really an piece of exciting news. It was finally there! I have downloaded the snapshot binaries and installed it. Compared to Matisse version, some of the API has been changed besides the package name(It is named under javax.swing package). I think at least changes to make use of JDK group layout in both Matisse and JDK.
1. The matisse code generator should be changed to use JDK GroupLayout.
2. GroupLayout should also be back ported to 1.4 and 1.5 so that NetBeans don't have to bundle its own group layout.
Now, NetBeans does not support mustang officially. We have to wait until mustang final release comes out. But anyway, we've got the excited news that it is going to be integrated into mustang.
Finally, it is there!
Cheers.