My servlet's destroy() method is never called. Is this a bug in WebSphere, or am I doing something wrong?

No it is not at all a bug. but it is a good practice if you write the destroy() method and destroy your servlet because if many servlets running on the same webserver are not destroyed explicitly, then the performance of the web server falls down.

[In other words, destroy() is not guaranteed to be called... but if it is, you should make sure it works right. -Alex]