We integrated GWT in Tapestry in a basic but effective fashion. Tapestry does the "single click then display page" stuff and GWT does the interactive application functionality.
We treat GWT and Tapestry as separate projects, so the integration is light. Tapestry has a template page wrapper around the GWT html page. GWT receives a few parameters encoded in the starting HTML page (rather than trying to extract out of the http session). I would be interested to hear where you get to on your tighter integration plans and what works. Szemere
