"Cool URIs don't change." Link rot is the biggest threat to the World-Wide Web. In my view it's irresponsible to issue a URL without being confident I can keep it available at least as long as the document exists. I don't have that kind of confidence in the government of Libya or Tonga decades from now.

I'm also not a big fan of redirections that cross failure domains, just because they make the web slower and less reliable.