Implement support for parallel deployment. This allows multiple versions of the same web application to be deployed to the same context path at the same time. Users without a current session will be mapped to the latest version of the web application. Users with a current session will continue to use the version of the web application with which the session is associated until the session expires. (markt)
Mehr Änderungen unter http://tomcat.apache.org/tomcat-7.0-doc/changelog.html.