The semantics of Request-URI are unambiguous in RFC 2616;
The Request-URI […] identifies the resource upon which to apply the request.
Period. Over and out. Elvis has left the building. There are dozens of commercial and open source implementations, and thousands of deployed instances of those implementations, that count on that being the case.
Now, if you buy the position of the WS-Addressing WG (and possibly even of the XML Protocol WG in the form of SOAP 1.2), they’d have you believe that the Request-URI identifies the next hop in the chain. Note that this definition is different than the previous one.
Note to my friends; if you ever find me advocating a position that attempts to redefine, in a non-backwards compatible way, a key part of the most successful application protocol ever developed, you have my permission to shoot me. Thanks.