I've been doing some thinking lately about blog genres, to see how they might translate into other media.
1) "Hotlink" blogs. Perhaps the original blog genre, links to stuff that is cool or interesting in the eye of the blogger. Boing Boing is a good current example.
2) "Diary" blogs. I think LJ falls into this genre. A lot less emphasis on crosslinking/syndication.
3) "Journalism" blogs. People engaged in a venture of some sort, chronicling it for the world.
4) "Editorial" blogs. These bloggers like to pontificate on issues of the day. A lot of the "war blogs" fall into this category.
5) "Narrative" blogs. These are the rarest, I think. Fiction or humor blogs.