I think I won't say anything new by repeating that a JAXRS specification has been a success.
It brings so many new annotations into a Java code but the main goal behind it, at least as far I see was to popularize the REST paradigm among java developers and surely, the goal has been achieved.
Marc Hadley, Paul Sandoz and indeed all the experts who contributed to the JAXRS specification have done a fantastic job. And no doubts more is to come from newer versions of JAXRS.
So here's my wish list. It's not a long one. May be it's a bit early given that JAXRS 1.0 was only released last September but here it goes :
Please focus on the Portability.
There's no uniform way to express that a given service class is a singleton. There's no portable client api - why is that ? In JAXWS one can do a portable code which creates and consumes services. There's no uniform way to query for a document describing a service.
That's it really - not a long list indeed :-)