This is definitely something that Rajeev should look at since I didn't have much to do with this part of it.
On a relatively superficial look everything looks ok, but it seems like there should be tests that explicitly cover all the cases of trying to log branches/messages to a logger before the top logger has come back across the wire. http://gwt-code-reviews.appspot.com/550801/show -- http://groups.google.com/group/Google-Web-Toolkit-Contributors
