Law review article citing blog posts: This isn’t an entirely new phenomenon, but it’s relatively new, and still interesting:

19. As initial commentary indicated, the Eldred opinion itself offered surprisingly little discussion of how it fit into either the First Amendment or the Article I federalism case law. See Jack Balkin, Is the Digital Millennium Copyright Act Unconstitutional under Eldred v. Ashcroft? (January 18, 2003), at http://balkin.blogspot.com/2003_01_12_balkin_archive.html#87596430 (discussing whether, with respect to the First Amendment, Eldred’s deference toward traditional copyright protection would not extend to recent innovations in the Digital Millennium Copyright Act); Orin Kerr, Eldred And Limited Powers (Jan. 17, 2003), at http://volokh.blogspot.com/2003_01_12_volokh_archive.html (suggesting that although Eldred may seem inconsistent with the Court’s recent Commerce Clause cases, Eldred did not involve the same conflict between state and federal powers); Eugene Kontorovich, Constitutional Law And Tradition (Jan. 18, 2003), at http://volokh.blogspot.com/2003_01_12_volokh_archive.html (suggesting that Eldred’s First Amendment result represented a reliance on tradition, which could lead to similar reliance in other First Amendment areas). . . .

44. For an early commentator suggesting that Eldred be best explained as traditionalism, see Eugene Kontorovich, Constitutional Law and Tradition (Jan. 18, 2003), at http://volokh.blogspot.com/2003_01_12_volokh_archive.html (“Basically the Court’s opinion says this is constitutional because no one, especially the Framers’ generation, ever thought it was unconstitutional.”) and Philippe de Croy, Constitutional Law and Tradition (Jan. 18, 2003), at http://volokh.blogspot.com/2003_01_12_volokh_archive.html (citing to Justice Scalia’s classic statement of traditionalism in Rutan and expressing skepticism that Eldred would have much effect on First Amendment law in other areas). . . .

99. Glenn Reynolds, Copyrights and Creativity (Jan. 16, 2003), at http://web.archive.org/web/20030207033652/http://www.msnbc.com.news/856672.asp. . . .

. I suspect that it will be especially common for articles about recent developments, where there isn’t yet any “official” commentary in published law review articles (or even in law review articles that are in draft), but only the unofficial commentary in academic blogs.

UPDATE: As I mentioned, this wasn’t the first example, nor the most prestigious one — my colleague Stephen Bainbridge’s blog made it into the Yale Law Journal. Cool.