I've created an initial branch with the changes needed to make errai work with cordova. I also have an example setup on how to use this, but I don't know where to put it (I guess that jboss-jdf would be a place for this?)
With regards to the cordova gwt wrappers there is already an open source project that has done this: http://code.google.com/p/gwt-phonegap/ should I make it a dependency of errai-cordova?