HN should do a HTTP HEAD on submitted URLs and change them according to redirects.
Edit: Doing an HTTP HEAD on the submitted URL—37signals.com/founderstories/—gave me an HTTP 302 "Found" (with Location 37signals.com/founderstories/slicehost). According to the HTTP spec, with an HTTP 302 you're indicating that "the client SHOULD continue to use the Request-URI for future requests"—strictly, shouldn't this be an HTTP 303 "See Other"—"the new URI is not a substitute reference for the originally requested resource"[1]?
Edit: Doing an HTTP HEAD on the submitted URL—37signals.com/founderstories/—gave me an HTTP 302 "Found" (with Location 37signals.com/founderstories/slicehost). According to the HTTP spec, with an HTTP 302 you're indicating that "the client SHOULD continue to use the Request-URI for future requests"—strictly, shouldn't this be an HTTP 303 "See Other"—"the new URI is not a substitute reference for the originally requested resource"[1]?
[1] http://tools.ietf.org/html/rfc2616#section-10.3.4