I don't know why or what the rules are, but in the eyes of the media, he is considered a blog and is usually the very first example given of a blog.
They've even nicknamed him the "grand daddy of all blogs".
I suspect it is someone with impeccable journalistic credentials, just as the Corner at NR, or even perhaps even Veith or Olasky from here. If the media complains about the latter, they won't find questionable personal dirt - and will appear even more Christophobic than everyone knows them to be.
Matt Drudge? The MSM considers his site a blog?
Gee, no wonder why they're so out of touch.
Exactly. The word is becoming synonymous with writings on the web and that's just the way it has morphed. There's no sense in constantly saying "but he's not a blog" or "we're not a blog".