Languagehat links to a New York Times report on Pearson’s fair use suit against Little, Brown. The suit claims that Yiddish with Dick and Jane, which discusses adultery, drug use, and other adult issues, is not a parody and therefore an infringement:

The book, by Ellis Weiner and Barbara Davilman, with illustrations by Gabi Payn, states on the front and back covers, spine and copyright page that it is a parody. But the lawsuit says the book "is not a parody, but is an unprotected imitation" because it does not use the copyrighted characters "for the purpose of social criticism."

I can’t imagine that the courts would consider an alternative spin that includes discussions of adult issues to not constitute social commentary, especially in light of Sun Trust v Houghton Mifflin, which was decided in favor of The Wind Done Gone. We’ll see.