If you haven't spotted it already, there's a new article as part of the IBM WebSphere Technical Journal on developerWorks, called:
"The Support Authority: JVM enhancements that help you see how your WebSphere Application Server is behaving"
Recently, a number of new enhancements have been made to the serviceability features within the IBM® Java™ Virtual Machine. These improvements have been delivered as part of Java 6 R2.6, the latest release from the IBM Java Technology Centre, which underpins IBM WebSphere® Application Server V8. Some of the improvements have also been delivered in Service Refreshes of Java 6. 1.This article discusses each category of improvements that have been made, and how they can help you better understand the behaviour of your application running on WebSphere Application Server V8
The article is written by Ian Partridge and Adam Pilkington who are part of the IBM Java development team.