The problem was:
16:38:07,433 ERROR [StartupServletContextListener] Error initializing ServletContext
java.lang.IllegalArgumentException: Class org.jboss.portal.faces.portlet.JSFMetaBridgeViewHandlerImp
l is no javax.faces.application.ViewHandler
Which is consistent with deployment isolation issues. It turns out that you can't isolate the right classes between a 2.6.0 install of JBoss Portal and certain legacy JSF servlets. The class cast problem will follow you around.
The fix is to head on over to:
checking that out and running build/build.sh deploy on that... (make sure your JBOSS_HOME is set and no old versions of jboss-portal.sar are lying around). From the trunk directory...
$ export JBOSS_HOME=/usr/local/jboss
After that life in JSF land is good. Very vexing problem if you are doing anything in JSF not specific to JBoss Portal