An anecdote, for whatever it’s worth: when my 33-month-old son saw me take Goodnight Bush out of the mailer, he said, “That’s my book!” When I explained that it wasn’t Goodnight Moon and we compared the two side-by-side, he said, “They match!” Then he insisted that I read him Goodnight Bush, though he soon lost interest. I don’t think his reactions are all that significant in terms of consumer confusion, given that a kid familiar with Goodnight Moon is unlikely to (a) be the purchasing agent or (b) be in the market for a second copy.
(Keep an eye on the Georgetown IP Teaching Resources RSS feed for a couple of scans for comparison purposes. Also, the news & reviews section on the official site, linked above, appears carefully culled for litigation purposes, focusing on the repetition of “political” and “parody.” Here’s hoping it works!)
I found some of the “goodnights” bitterly funny—my favorite was the blank page “goodnight air” changed to “goodnight allies.” The Twin Towers are alphabet blocks; Jesus rides a toy dinosaur for “goodnight evolution.” All in all, it’s more satire than parody, to the extent that one can tell the difference, though it does highlight the surrealism of the original Goodnight Moon as well.