As of today, there are already 3 Java EE 7 compatible Application Servers, coming from different 'vendors' (Oracle, TmaxSoft and Red Hat). Two of those Java EE 7 Application Servers are free and open source. We expect the list of Java EE 7 compatible Application Servers to grow over the coming months.

Source: RebelLabs - 'Java Tools and Technologies Landscape for 2014'

According to a recent independent survey, one third of the Java EE users who participated in that survey is already using Java EE 7. This is a good sign but it also means that a lot of people are not yet on Java EE 7. So if you haven't yet embarked on Java EE 7, now is really the time to do so!

• Continue to read The Aquarium. Through this blog, we are relaying Java EE news but we are also doing our best to highlight relevant technical contents such as articles, community tutorials, etc.
• Watch the GlassFish YouTube channel. Amongst others, it contains the different videos of the Java EE 7 launch, those videos will give you good technical update on Java EE and its different components specifications (JMS 2.0, JAX-RS 2.0, EJB 3.2, etc.)
• Take a formal training. Oracle University is starting to roll-out Java EE 7 trainings like the 'Java EE 7: New Features' class. 
• Attend conferences and JUGs sessions. On that note, we have spent a lot of time to create a strong JavaOne 'Server-Side Java' track. It's still possible to benefit from the early bird JavaOne pricing but don't wait too much!
• Read books. There are more than 25 (!) books related to Java EE 7 or to one of the Java EE 7 component specification. 

And finally as the introductory quote suggest, participation is key to learning. Participate in JUGs,  participate in Adopt-a-JSR, get involved in the different open source communities evolving around Java EE, participate in the JCP... in one word, participate!