W3C TAG posted a note that it is against XRI.
http://lists.w3.org/Archives/Public/www-tag/2008May/0078.html
Here is the arguments that lead to the above decision.
http://lists.w3.org/Archives/Public/www-tag/2005Apr/0095.html
http://lists.w3.org/Archives/Public/www-tag/2008Feb/0009.html
Unfortunately, the recomendation does not specify what exactly is unhappy about. So, I was going over each reason sited in the above documents (which has been replied by Gabe Wachob before.)
1) All access to resources identified by XRIs
require (at least) two round trips, the
first to retrieve metadata (XRDS, XRD or
uri list) and the second to retrieve
(a representation of) the resource itself?
Quite right. And if it were just for simple resolution of XRI, XRDS probably would not be required, but as a service selection language as used in OpenID, it would be very useful. It would also provide a sort of failover capability. Thus, at a glance, the requirement to make two round-trips to get to an actual resource is a burden, it has the merits.
2) HTTP content negotiation can be used in
requests for XRIs to force either metadata
return or redirection to actual resource
representations?
This actually is what is being done in XRI specification for HTTP binding. (XRI Resolution Section 6)
For non-http protocols (well, XRI does not have to be on TCP/IP network), of course, it cannot.
Looks like W3C TAG is assuming everything would happen over TCP/IP and HTTP forever.
3) Relative XRIs are of course allowed in the
normal way when a full-form XRI has been
established as the base URI. Are they also
allowed _without_ any full-form XRI as a
base URI? That is, for example, is “=henry”
intended to be recognize as an XRI in the
absence of any base URI? If so, what is
being done to ensure that both now and in
the future, the syntax of such abbreviated
XRIs is coordinated with (I.e. remains
disjoint from) the syntax of both absolute
and relative URIs that might be used in the
same contexts?
Refer to Gabe Wchaob’s response.
Also, could you let us know what steps, if any, you have taken towards registration of ‘xri’ as a URI scheme with the IETF?
No. It is supposed to be registered only after the vote.
The recommendations that we have documented in Architecture of the World
Wide Web, Volume One state that “A specification SHOULD reuse an
existing URI scheme (rather than create a new one) when it provides
the desired properties of identifiers and their relation to
resources.” [2] In this case, a properly managed and supported use of
the existing http scheme, based on the excellent analysis in your
documents, does have the desired properties and can provide the same
functionality without the loss of interoperability which would
accompany a new scheme. (ref)
I agree that we should try to reuse existing scheme, but using http:// scheme based URL for a non HTTP protocol such as gopher: seems a bit awkward and confusing at best because for many people, http: would have concrete meaning.
I suppose that it is a scoping problem.
If we assume the world of WWW only, TAG response would probably merits the point. However, we do not live in WWW only world nor will be.
my 2c.
For other comments, see OASIS XRI Wiki Page