I am building a web application on top of a "custom" web framework. This framework is essentially the Equinox OSGi platform with Jetty sewn into a custom bundle (not the Equinox-supplied one, mind, as it is far too restrictive).
This framework is being used to build a large Java web application, primarily using JSP. No other frameworks (Struts, JSF, etc.) are being used, and adding them into the mix is not a straightforward procedure as Jetty does not appear to allow you to programmatically register taglibs by URI.
This web application needs to be structured such as to provide easy extensibility (taglibs, add-on libraries, etc), easy reusability (e.g. "user controls") but must be extremely stable. Once this system is running, there will be a period of time during which there won't be a lot of manpower available to fix problems as they happen.
In your experience, would this warrant shifting the entire project over to a proven servlet container like Glassfish, Tomcat et al., or would it be better to stick with the aforementioned custom framework and the nuances that go along with building custom frameworks from scratch?