I think you should seriously reconsider.
I would *LOVE* to use java as a replacement for Windows C++ development. But for my applications to depend on a 15 MB framework is simply inacceptable.
So as suggested a smart linker (just like Delphi's linker) that omits all methods that are not required would be fantastic.
I don't know if you have to open source JET to use the GPL'ed version of Java. I mean there are form editors for wxWidgets (which is released under the GPL) which are not open source and sold commercially.
Also, you can statically link wxWidgets applications to produce small (~ 500 KB) windows apps.
Unless it is possible to *reliably (e.g. no GCJ windows hacks) * produce native Windows executables, I don't see any future for Java on the desktop.