JAX-RS 2 is one of the most significant parts of the upcoming Java EE 7 release. In a brief article, consultant, German author and celebrated Java EE advocate Adam Bien does a great job of overviewing the major changes in JAX-RS 2. He talks about asynchronous processing, EJB/CDI integration, filters/interceptors, the configuration API, the client API and more.
If the article whets your appetite to learn more about JAX-RS 2, you could download the actual proposed final draft and give it a read. For those unaware, JAX-RS 2 recently passed its public review ballot. At just above 90 pages, the actual JAX-RS 2 specification document is not that bad of a read.