It might be old, but then so is the JMS specification - the
current version has been around since 2002. Looking at the table of contents there doesn't appear to be anything earth shattering about it. But, hey; if you can pick up a second hand copy for 24 cents, and you've the time to read it, why not. Personally, in the context of this exam, you're probably better off browsing through the
Enterprise Integration Patterns website. If you still feel like you want to know more - buy the
book
SCJP, SCWCD, SCBCD, SCEA 5