A large part of the day vanished down a rat-hole that persistently sucks in time; in our internal jargon we call this "the HTTPRange-14 issue" and it's all about what the "R" in URL stands for. Well, it stands for "resource", but what's a resource? Well, OK a web page, but lots of URIs point to things like robots and weather forecasts, and some people use them to point at cars and organizations and so on, and this makes some other people uneasy.
Someday I'll write an essay here about resources and representations and so on, but those who care can visit our public mailing list and read hundreds of well-informed and passionate notes on the subject.
Here's a picture of Dan Connolly whiteboarding part of the problem.