I've created an application status page that it's very similar to the service status that is bunbled with the framework but instead of showing information on services it shows information on the web application itself.
You can check out the code for it and a screenshot here http://hugopalma.wordpress.com/2009/06/24/tapestry-application-status-page/ I would also like to know if you guys think that such a page should be included in the framework itself. If so i'll gladly create the issue and appropriate patch. Cheers, Hugo