JAX-RPC 2.0 (Java API for XML Based RPC) has been renamed to JAX-WS 2.0 (Java API for XML Web Services).
This was done for a number of reasons, but the main reasons are:
The JAX-RPC name is misleading, developers assume that all JAX-RPC is about is just RPC, not Web Services. By renaming JAX-RPC to JAX-WS we can eliminate this confusion.
JAX-RPC 2.0 uses JAXB for all databinding. This has introduced a number of source compatibility issues with JAX-RPC 1.1 because the bindings are different. The migration from JAX-RPC 1.1 to JAX-RPC 2.0 is not cookie cutter as generated Java code and schemas will be different than those generated by JAX-RPC 1.1. Although the renaming does not ease this migration, it does let the developer know that these are two separate technologies, hence the more difficult migration is more palatable.
Maintaining binary compatibility with the JAX-RPC 1.1 APIs, was hindering our goal of ease-of-development. Because we had this binary compatibility requirement, many legacy APIs were exposed such as the various methods on javax..xml.rpc.Service and the javax.xml.rpc.Call. Having these legacy APIs around would confuse developers. By renaming JAX-RPC 2.0 to JAX-WS 2.0 we no longer have this binary compatibility requirement and we can rid the APIs of these legacy methods and interfaces and we can focus on a new set of APIs that are easier to understand and use.
For more information on JAX-RPC and JAX-WS 2.0 check out the JAX-RPC project