not trying to revive an old thing, however, I use the OED/Cambridge as an authoritative source.
Journalist:
a person who writes for newspapers or magazines or prepares news or features to be broadcast on radio,television or newspaper.
Blogger:
a person who writes for a blog
Gizmodo parent company, declares Gizmodo a blog. Anyway, back on topic...
Yes, but at one point radio was not included in that list as it did not exist. Similar to blogging.
It's time to edit that entry in the OED/Cambridge.
A blog is a new form of journalism.
As I said before, the courts will decide. It may take years, but we'll see blogs added to that list.