There's an article here on academic blogging which people reading this might find interesting. (Thanks to Daniel for the pointer.) I agree with many of the sentiments expressed, though if 'younger scholars' are really worried that 'blogging would eat up time that could be devoted to publishing articles or working on a book', that would seem to be a mistake - at least in philosophy (although I would have thought in other discipines too) ideas floated as blog entries can later become bits of papers or books, having benefited from commentators' feedback. (Or that sort of feedback could help you realize that an idea isn't worth pursuing sooner than you would have otherwise - also very useful if you want to spend more time getting your better ideas into print ...) Blogging isn't 'conventional academic writing' but it's capable of being as much a preamble to it as a good seminar is. Particularly if you're someone who finds (as I do) that making yourself write something down is a good way of getting it clear(er).
OK, that's enough self-justification. Back to my conventional academic writing.