I am using GWT 1.5.3 for mac
the palette shows up now after I got the module xml correct.
I copied the EXT JS files, adaptor, resource from "Ext 2.02" to public folder as your sample project.
I was able to do GWTCompile, and then run it as GWTApplication, I got the blank screen, nothing shows up on the page, the page is very simple with one GWT-EXT button.
I tried to attach the project as a zip, but I got this message on the page: "The file is too big, maximum allowed size is 256 KiB."