As you might be aware, the initial wave of Java EE 8 JSRs are now launched, including the platform JSR itself, CDI 2, JSON-B, JMS 2.1, Servlet 4, JAX-RS 2.1, MVC and JSF 2.3. Most of these JSRs are now actively looking to form their initial expert groups, including JMS 2.1 (filed as JSR 368). JMS 2.1 specification lead Nigel Deakin has written up a very handy guide on joining the JMS 2.1 expert group. In fact the guidance applies very well to most JSRs, so it is definitely worth a read if you have an interest in joining a JSR. As you can expect, applications to join the expert group are maintained completely in the open. The current nominations for JMS 2.1 are listed here.
JMS 2.1 will largely continue the focus on API modernization started in JMS 2.0. While we worked primarily on synchronous send and receive, this time the expert group will hone in on improving receiving asynchronous messages - hopefully resulting in a more powerful and simpler alternative to JMS Message Driven Beans (MDBs). Some initial ideas towards this can be found here andhere. There are of course many other items under consideration such as improving JMS provider pluggability, redelivery delays, redelivery limits and dead message queues.
Note that you can always participate in a JSR without officially being part of the expert group by simply subscribing to the JSR user alias. In case of JMS, that alias is users at jms-spec dot java dot net. Also remember that you can contribute on an even more lightweight format throughAdopt-a-JSR. If you have any questions about participating in JMS 2.1, you should feel free to email Nigel directly at nigel dot deakin at oracle dot com.