Reader Fritz Schranck points out that the Delaware journalists' privilege covers, in relevant part:
any journalist, scholar, educator, polemicist, or other individual who either:
a. At the time he obtained the information that is sought was earning his or her principal livelihood by, or in each of the preceding 3 weeks or 4 of the preceding 8 weeks had spent at least 20 hours engaged in the practice of, obtaining or preparing information for dissemination with the aid of facilities for the mass reproduction of words, sounds, or images in a form available to the general public; or
b. Obtained the information that is sought while serving in the capacity of an agent, assistant, employee, or supervisor of an individual who qualifies as a reporter under subparagraph a.
I love how this includes "polemicists." Just try arguing that bloggers (assuming they're professionals) wouldn't be covered by that!
UPDATE: Thanks to reader Eyal Barnea for correcting an error in my original post; I had misread the statute and concluded that it required the blogger to be a professional, but of course it requires that or spending a lot of time.