Tomcat 6 supports the Servlet API 2.5, so it won't work. Tomcat 7, on the other hand, supports Servlet API 3.0. You may have to install JSTL 1.2 and JSF 2.0 separately, though. Or you can use a container that's guaranteed to support all of that out of the box, like GlassFish 3.
subject: The server does not support version 3.0 of the J2EE Web module specification.