This week's book giveaway is in the OCMJEA forum. We're giving away four copies of OCM Java EE 6 Enterprise Architect Exam Guide and have Paul Allen & Joseph Bambara on-line! See this thread for details.
Has the book has enough coverage on CDI? Can you please elaborate a bit more on "extending enterprise applications" ?
The book covers some CDI recipes. But also aims to show how other technologies can be added to a Java EE project to extend your capabilities.
There are several aspectJ recipe's in addition to CDI.
There is also a chapter just on integrating JVM languages like Groovy, Scala, and JYThon.