Interesting. It was not very long ago that the same Matt Cutts was encouraging guest blogging as a legitimate way to build backlinks. It has always been considered legitimate as long as the posts are in sites related to your site and you write quality content. So does that mean that they will now start penalizing all the millions of guest posts out there?
Pretty soon they will not want us to post anything to our own blogs.
This is just another of many, many reasons to strive to abandon all things related to Google.
"Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote." -- Benjamin Franklin