JR Minkel did a story on evolved sex differences for Scientific American ("Student Surveys Contradict Claims of Evolved Sex Differences"). Personally, I never take the results of student surveys to be good evidence about psychology. But the reason I'm pointing to the article is that Minkel posted on his blog the critical commentary he received from David Buss ("David Buss defends evolved sex differences (exclusive!)").
In this case Buss wrote in response to an invitation. I wonder what would happen if this approach was more widespread -- articles about science accompanied by e-mail commentary from the scientists. Maybe the journals ought to pay them in that event. But there are a lot of crummy stories (not necessarily this one) where I, as a reader, wish I could read more of the scientist's opinion than the short quote that the journalist may have used.
I suppose if I got called upon to do this, I'd get tired of it pretty quickly. Or be like, "Dude, read my blog."