The question has returned from the dead yet again. At this point, I am tempted to suggest that the answer is "blogging is scholarship whenever an academic reader decides that it is"; some of my blog posts have found their way into the footnotes of peer-reviewed publications, for example, and one of them was even the partial topic of a conference paper last summer (!), so...presumably they have "become" scholarly, despite their conspicuous lack of peer review? Or does online readership count as open source peer review? In any event, under the circumstances, it seemed silly to leave the blog entirely off my CV, so I stuck it under "Miscellaneous Writing." (It's not this thing, it's that thing, it's...some other thing.)
At most, I think of my scholarly posts as drafts-in-public--or, if you like, as performances of scholarly process. In that sense, they're "scholarship," but they aren't "scholarship" in the sense of "does my university 'count' this as scholarship when I apply for a merit bonus." (Which makes me wonder if by "scholarship" we mean "what my university counts as such on an annual report.") For example, I've done a couple of Bronte-related posts over the past few weeks, which relate directly to the article I'm working on (and, um, am supposed to be finished with by now). But the article doesn't simply repackage the blog posts--if anything, what once occupied an entire and reasonably substantial post now boils down to a few entirely-revised sentences. Similarly, Book Two draws on some material I posted on Scott, but the material in the book bears not much resemblance to the original blog post, aside from working from the same quotation. There's certainly an argument to be made that drafting in public serves a useful function beyond any feedback, but the results are still only the first stage of what I would consider a finished product.