Undeservedly short answer to the excellent questions asked by Ernie the Attorney here:
Denise does not likely have nationwide common law trademark rights in the term BLAWG even though she coined it because, as far as I know, she does not use it as a trademark. Specifically, she uses BLAWG to describe the class of blogs known as law blogs, and does not use it to identify a source of goods or services.
She does appear to have nationwide common law rights in the mark BAG AND BAGGAGE for the provision of legal information. She could also consider coming out with a line of BAG AND BAGGAGE items similar to those she discusses here.
One wonders what would happen if another attorney name Ernie was to advertise himself as ERNIE THE ATTORNEY. One may use one’s own name to identify themself (as our readers know) unless such use causes confusion. I would happily sign an affidavit that to me, the mark designates no one other than blogdom’s Ernie (and his place on the Userland Top 100 would be good additonal evidence of h sucsecondary meaning).
Inherently registrable blawg names include Bag and Baggage, InstaPundit, How Appealing, Copyfight, Excited Utterances (one of the great blawg names), and LawMeme, as they are either coined, arbitrary or suggestive of law blogs.
Attorneys Suck describes one quality of the provision of legal information and would require secondary meaning to be protectable as a trademark.
As for Trademark Blog, it’s a good thing I own the domain name.