I have just returned from the AAPT (American Association of Physics Teachers) national conference. One of the workshops was "Blogs, Wikis, and Forums".
We were a relatively savvy audience - most of us know of the technologies, some had used them, fewer had used them in class. Once I get my camera out of our overloaded car, I'll download the pictures.
Other references to blogging in academics:
west of the moon: academic blogging
Teaching with Blogs: Always Something New