Why isn Firefox 2 supported by the New Plug-in?
Sun has been working closely with the Mozilla foundation in order to get the New Java Plug-in supported in Firefox 3. Both organizations have mutually decided not to back-port the required changes –which are significant– to Firefox 2, as it is expected that most Firefox users will upgrade to Firefox 3 a short time after its final version has been released. The ‘classic’ Java plug-in will be used by default with Firefox 2, even if the New Plug-in has been turned on.