It looks like SpringSource has just released a GA version of their tc Server application server.
It sounds from their description like it is a drop-in replacement for Apache Tomcat, with better "enterprise capabilities", such as "advanced diagnostics", better operations management, deployment, etc. (and of course, the support that they want to sell you as their primary business model).
So I'm curious (and I'm not sure if this is truly a SO question), but is anyone using tc Server today in any shape or fashion? Has it worked out well for you? Did you find whatever features they are adding to Tomcat to be worth it?