This week's book giveaway is in the OCPJP forum. We're giving away four copies of OCA/OCP Java SE 7 Programmer I & II Study Guide and have Kathy Sierra & Bert Bates on-line! See this thread for details.
Developer Studio is fine if you are targeting JBoss EAP. It is configured to be closely integrated with EAP, and should work very well with the version of JBoss AS that was used for EAP. However, if you want to use the latest features and releases, then stick with Eclipse + JBoss Tools.