I have the same problem. I bought a license because I saw that Tomcat 7 was supported, but when I add the Java component to my Plesk Panel it installs the Tomcat 6 version.
I'm using the Official Plesk Updates server.
I did install Tomcat7 from the repository that IgorG said (JPackage) but how can I tell Plesk to use it instead of Tomcat 6? I've been searching for a day and I can't find the way to integrate it.
Could you help me?
Thank you,
Àlex