JAX-RS 2.0 provides enhancements to the JAX-RS API that allow for more powerful RESTful services. Key new features include a client API, filters and interceptors for customization, bean validation integration, and support for asynchronous processing. The client API allows building and invoking requests in a standard way. Filters and interceptors provide extension points for tasks like logging and compression. Bean validation leverages existing JSR 303 annotations. Asynchronous processing supports suspending and resuming requests.