Blogscholars?
There are a number of academic bloggers who do an excellent job of talking about their scholarship, but that again is not in and of itself"scholarly activity": it's like writing an abstract for a book or conference paper. And, as Matt Weiner points out in Unfogged's comments, there's nobody to stop you from blogging something inane or just plain wrong (although there are plenty of people out there who will, after the fact, gladly point out that you've done so).
That said, there are a number of bloggers out there who could probably claim credit for their blogs as service credit (e.g., running a blog dedicated to the activities of a professional society) or teaching credit (e.g., developing a group blog for classroom use). But blogging's appeal--the ability to post"to the moment," to write informally and without the intervention of an editor, to interact immediately with an audience, and so forth--seems, if anything, to militate against the kind of ongoing work (and, quite frankly, real drudgery) involved in scholarship. You can get instant gratification from a blog post, but not from that article on Emily Sarah Holt you've been writing for the past two years. [X-posted and slightly edited.]