My only take on the whole linking/credit debate, @mathewi @tcarmody @felixsalmon @palafo (and I admit I may have missed some part of the convo) is that it's hard to know whether the second reporter saw the first story and then set about trying to "match" it (that's the AP term, by the way, for it), or the second reporter had his own sources and reporting but was just beat to publication.
Before I would complain, I'd figure that out first. Anyone who's worked in a competitive, breaking news environment knows that there are often multiple sources of information. People talk. So if someone followed my story with something nearly identical, I wouldn't assume that he simply matched it.
As for whether reporter #2 should credit or link to the first post, I think it depends on how much work the second reporter did to push the story forward. Did he get an on-the-record source to confirm it? Did he get a key interview?
We should tell people where we got the information we used in our stories, but we aren't obligated to tell them everything related to how we got it. Otherwise we'd be paralyzed trying to remember what New Yorker article two months back we're riffing off for a blog post today. So actually I do think this is more a matter of politeness or collegiality than ethics.
I am so glad I spent this time getting this off my chest.