Thank you for creating this bug report. I had a few additional comments.
We already have over 13 portlet applications that are running on the MyFaces portlet bridge version 1.0.1. I don't have the proper authority to change all the faces-config.xml files to add the required tag to upgrade to version 1.0.3 of the portal bridge. We may have to wait until this bug is fixed in version 1.0.4 to pick up the new version, unless I can get everyone to change their file.
Since the default-render-kit-id tag has now become mandatory (at least for version 1.0.3) the documentation should be updated to remind user to add this new tag. Otherwise you will have some confused customers. I could not find much information about the default-render-kit-id tag on-line. The documentation should list the default value "HTML_BASIC" because this was not obvious to me when I was looking for a solution.