After making some changes to our Jenkins chef recipe I redeployed to have it error out with:

FATAL: Net::HTTPServerException: http_request[HEAD http://updates.jenkins-ci.org/latest/github.hpi] (jenkins::default line 70) had an error: Net::HTTPServerException: 404 "Not Found"

It seems as though all the other http://updates.jenkins-ci.org/latest/"name" links are working fine; and trying to visit http://updates.jenkins-ci.org/latest/github.hpi for a direct download does result in a page not found on the browser.

I've been able to reproduce the issue twice; once while reverting to a previous known working commit.