GUI Builder Bi-directional Code Generation

Are there any plans to enhance the GUI Builder to parse existing code?
WindowBuilder Pro can parse Netbeans generated code and even hand written code
http://code.google.com/javadevtools/wbpro/features/bidirectional.html

Its open source now so you can even take a peek at how they do it :)
http://dev.eclipse.org/svnroot/tools/org.eclipse.windowbuilder/trunk/