At Crooked Thimber, Ezther Hargittai writes a long post about blogging and academic publishing. In this she argues that blogs should count towards academic publishing, because there are blogposts that are more carefully researched and better written than academic articles.
This is a very enthusiastic argument for blogging as an academic activity, but I am afraid it is a little naive as well as somewhat blind to the mechanisms of professionalisation and the limitations of blogging.
Blogging is an exellent medium for a wide range of things, but not for assuring a consistent minimum of quality. The desire to look as good as possible to the public can make the write deliver well considered and good material, but there is no system which guarantees that every blogpost has been subjected to scrutiny and criticism by at least one person other than the blogger. Of course, there is no reason why blogs should not make such a system, have an editor and an editorial board, and the post will only be accepted if this group of reviewers have read it. But there are media like this already active in academic publishing. They call them journals.
This does not mean that blogs are useless to academics. No, they are very, very good for creating your own profile, an online presence. They let others see what you work with and where you are, and if you have managed to get over a few thresholds and are fairly easy to "hit" when somebody googles your name, the chance that you may have invitations to interesting conferences or to participation in research and teaching or other interesting, relevant things rises sharply.
Much of the debate around academic publishing and the need for blogs to fill a niche in that field has nothing to do with the failure of journals to publish the interestign and important stuff, but a failure in the US educational system in assessing their own employees. First, the need for assessment is enourmous, as there is supposed to be a constant competition. The American dream is based on competition and survival of the fittest. In Academia this comes out as "survival of the person whocan get the most articles published." For anybody who have the slightest understanding of why something gets published, it is obvious that a system like that will statistically be concervative and preserve already accepted values. Read Galtung and Ruge for a basic understanding of news values, the same mechanisms are (with some slight adjustments) valid in all types of publishing.
Second, the assessment needed to constantly maintain an air of fair competition is very, very expensive. So instead of doing this themselves, Universities and Colleges all over the US give that task to the editors of journals. Because the scholars need a positive assessment, the journals need content and the Universities need a free system for assessing the work of scholars, we get a trinity of mutually dependency where all appear to benefit.
And everybody do benefit - until a scholar thinks a new thought. As soon as somebody works on something which is innovative, which is different and strange, something not yet over the threshold of academic publishing, they will be kept back by the concervative nature of this system. This is where the enthusiasts dream of blogging as academic publishing, accpted into the struggle for tenure.
I don't think that's a good substitute for the traditional academic publishing. I do however think a blog can make something more acceptable. Blogging works virally, new concepts spread with lightening spead, and a good concept can catch on in a matter of months. This is not a bad thing for the new, young scholar, because this means that a new concept can become/appear established in a very short time. A blog will also ensure that the assessors can find the references to key concepts in your work easily, and a good blogpost may give further depth to an argument.
So I think my personal and subjective conclusion is: No, blogs can not fill the position of the journal article in a process where you are constantly assessed and compete with others who are constantly assessed - unless the Colleges and Universities put a whole lot more resources into the assessing process than they do at present. Yes, blogs can be very useful, particularly in situations where a comittee is forced to make a judgement call, or when it comes to creating and maintaining networks.