Andem - 11:04 pm on Nov 14, 2011 (gmt 0)
I'll try to give some insight, rlange.
News sites are known to frequently update previously published stories about ongoing events as new information comes in. I don't know how sites like CNN operate on the backend, but is it possible that these updates trigger a republishing of the story?
Google News updates work on a url basis. It used to be that they would identify a unique number id in the story url and not consider it republished unless the unique id number changed. Now, Google will view an updated URL as a new story without regard to the number id. Usually all they have to do is change a character in the story URL and it's now considered a new story.
Our URIs contain a couple of words from the headline and a unique story id. If I've noticed a typo in the headline and changed it after Google has grabbed it, the new url will appear as a new story and get a 5-120min boost.
A note: I noticed Google News uses news sitemaps now. We have been listed since far before news sitemaps were introduced and hence are perhaps legacy publishers. I don't know if G News treats sitemap news differently.