The past few weeks has seen Nature (and Nature Neuroscience) run a series of features about science communication - science journalism, science blogging, and so on. They're all worth reading, and very readable, but, perhaps inevitably they raise more questions than they answer.
The basic assumption behind all of the articles is that communicating science to the public is A Good Thing, and scientists should be trying to help with it - whether by blogging about science, or helping to write press releases, or talking more to journalists.