JAX-RS 2.0 Early Draft Third Edition is now available. This updated draft include new samples explaining the features and clarifications in content-negotiation, discovery of providers, client-side API, filters and entity interceptors and several other sections.
Provide feedback to users@jax-rs-spec.
Jersey 2.0, the Reference Implementation of JAX-RS 2.0, released their fourth milestone a few days ago as well. Several features have already been implemented there. Note, this is an early development preview and several parts of the API and implementation are still evolving.
Feel like trying it out? Simply go to Maven Central (of course none of this is production quality at this point). The latest JAX-RS Javadocs and Jersey 2.0 API docs are good starting points to explore. And provide them feedback at email@example.com or @gf_jersey.