This may well be a first (and hopefully not too common an occurrence). Via Jeff Jarvis, a passenger who was in a plane crash in Denver literally Twitters from the scene as soon as he gets out. Surely cynical hack X can't still now say Twitter isn't useful to journalists. There you go, a perfect eyewitness for a pretty major story (although it probably helps to be on Twitter so you can introduce yourself before leaping in for an interview request).
The other argument I often hear against using Twitter, from a journalism (or PR) point of view is that it's impossible to find news like this because they don't how to follow and it's such a vast space that its impossible to stumble across anybody Tweeting breaking news.
Well, yes. And then no. Stumbling across a breaking news Twitter feed by chance would be pretty unlikely. But knowing how to target possible breaking news is another.
It's as simple as this: first set up a TweetBeep alert for stuff specific to you. Second, start using Twitscoop, which shows you a cloud of hot keywords being Tweeted. I've integrated the widget into my Netvibes, which I'm rarely off, so can pick up if something's got the site a-Twitter.
Finally, if news breaks, just use Twitter search to see who's tweeting about what. So, in this example, looking for plane crash, plane or even Denver would probably return a few relevant hits. Or, even better, if there's a hashtag, you've got all the content you need right there.
Once you've got this set up and into the mindset, you can probably have all the relevant information on Twitter in just a few minutes. I've even seen a journalist friend of mine Twitter that he's "grateful to TweetpBeep for giving him a story".
It's things like this that show why Twitter is so useful for breaking news and is not just some form of bastard child of the Facebook status.