Not Ready for RPC
In particular, however, those who view Web services as a remote procedure call technology for the Internet are bound to be very disappointed. Existing RPC technologies include the concept of a session, or connection. The Web involves a successful transfer of data and then drops the connection. RPC maintains the connection through the request and reply sequence. That way, the client, or requester, is guaranteed to either receive a reply or an error, indicating that the requested operation didn't complete. The reply message is tied to the completion of the program without an exception; otherwise, an exception indicates that the program did not execute to completion.
The trick in getting Web services to succeed involves bridging this difference or gap in understanding, background, and belief in the usefulness of technology. It is possible that Web services will not succeed because they cannot bridge this difference, but the promise of a Web services-enabled future is so great, the motivation is very high to make the marriage work.