JBoss AS 7 combines lightning fast speed and an IDE-friendly reduced footprint.  These attributes, combined with the easier programming model of JEE 6, have made programming fun again.  But to work in this environment, you'll need to learn how to configure and administer AS 7.  (That's what the book is all about.)  The author has already produced two well-written books on JBoss, so you have an assurance this guy knows what he's talking about.  The book can be found at Packt.  A full review can be found here