H-W, Chris, et al;
Some service providers already post system-wide planned outages and even
system-wide unplanned outages (like NSFnet backbone outages) on public
mailing lists.
We don't need another protocol to support this -- it would be a simple
matter for everyone to gateway system-wide trouble ticket reports to a Web
page.
As Chris points out, even if today we could do this, in future it will
become more difficult as competitive pressures mount. In the past I have
managed NOCs where there were pressures on the NOC to sugar-coat the public
trouble tickets. A certain amount of this is appropriate, since it is
possible for NOC controllers, network engineers and other technical support
people to become frustrated with their peers and I have some vivid memories
of particular frustrations coming out in system-wide trouble tickets. It
doesn't help either party for shouting and name-calling to show up in
trouble tickets, but it can easily happen, as we all know.
So when the pressure inevitably mounts on everyone to treat their
system-wide trouble tickets like press releases, the information content
that we seek will tend toward zero. Therefore I feel that if such a public
system were created it would inevitably devolve to minimize useful
information, such as who is really screwing up or where the difference of
opinion actually lies.
We need a new pressure point, like traceroute became for routing or
throughput became for router benchmarks.
If you all kept incident notes and someone sent out a survey every quarter,
would you be interested in a Consumer Reports style of NOC performance
metric? 
This might be worth thinking about in the IP Perf Metric BOF
next week.
I just don't see any other pressure point. There has to be an outside
evaluation tool and a general understanding of how to interpret it.
--Kent