The Weekly Standard seems to think so, based on the Hugh Hewitt essay linked above. He worries that Chinese, Russians, and international terrorists are spreading propaganda through blogs.
On the other hand, it seems to this reader that many Blogs are busy exposing propaganda spread by major media outlets, and are a good alternative source of information, a true "marketplace of ideas."
Of course, a few years ago the Weekly Standard had a cover story headlined something like: "Smash the Internet!"
So it sort of figures.