Assuming we like the concept, I have two issues noted here.
At the larger level, people should be doing this today in e.g. build.xml as a wrapper, which also works... I'm not sure whether I'd be more annoyed to fail on existing dirt, or to have something I'd tried to preserve be overwritten. The first, however, is annoying; the second is potentially costly! http://gwt-code-reviews.appspot.com/928801/show -- http://groups.google.com/group/Google-Web-Toolkit-Contributors
