According to the JCP, the upcoming, correct, and preferred way to enable JSP debugging is through support for JSR-045. MyEclipse has a fully compliant client-side JSR-045 implementation so that JSP source-level debugging will work on any server that supports the “other side” of the specification.
The servers listed in the header don’t support JSR-045 yet, so source-level JSP debugging is not available. However, as soon as they have a shipping implementation, it will be. Naturally, you can still debug all your deployed java code that is called from a JSP as you normally would, just not Java directly embedded your JSP pages.
JBoss is a bit unique since it bundles either Tomcat or Jetty as its webserver so you can read the above as saying that whenever JBoss comes bundled with Tomcat 5 or an upcoming version of Jetty that supports the latest Jasper2 implementation, and hence JSR-045, JSP debugging will be immediately available with that bundled version of JBoss.
–Scott
MyEclipse Support