The WikiPorlet stores the pages in /tmp. You can change this by editing the file wiki.ear/lib/wiki-common.jar/org/jboss/wiki/filedatasource.properties.
I have tried to move this properties settings from internal properties file to the portlet.xml, but it is not easy to implement.
Some Wiki classes are singletons and it was loaded for first by the classloader, I'm considering the potential useful of a Spring implementation.
But I think that before to start to do a similar implementation I need to refactor some source code parts to make more easy the development process.
I'll update you on this as soon as possible.