This is big news; well, at least it's big news in the blogosphere, which isn't to say that it's unimportant but that you won't find very much coverage of the issue in MSM.
Michelle Malkin has a history of what happened. The brief history: Jordan (the head of CNN) is reported to have said at a media conference in Davos, Switzerland, that American military forces have deliberately targeted and killed journalists. I say "reported to have said" because officials of the conference refused to release a videotape of the event and Jordan says his remarks were taken out of context. Some journalists, a few members of Congress, and an ordinary citizen were present and challenged Jordan's claim. They later broke the story in the blogosophere while MSM had no coverage until one or two days ago.
Instapundit has a roundup of links.