This week's book giveaway is in the OCPJP forum. We're giving away four copies of OCA/OCP Java SE 7 Programmer I & II Study Guide and have Kathy Sierra & Bert Bates on-line! See this thread for details.
No, JForum can't do that out of the box. And while it would be easy to configure all servlets and filters in web.xml twice for different URLs, it looks as if the path to the config directory is not configurable - so both servlets would use the same settings (and the same css, images and templates directories).