I was speaking last week at an Open Source Conference in Paris in the Java Application Server Track and from what I heard from the JBoss and JOnAS guys, it seems like 2007 will be the year when (almost) all app server vendors deliver Java EE 5.
Now that's not to say you need to wait for 2008 to start using Java EE 5. Some early Java EE 5 & GlassFish adopters have already been successfully deploying in production.