The Christian hate groups on TCGs are retarded. Didn't the pope praise M:TG as an effective learning tool for developmental children? I mean, you're life's gotta suck to be playing into your twenties, but I don't see why the religious hate.
On topic: It does seem like an out of the blue thing that Rowling just decided willy-nilly, possibly after reading rumors on fan sites. I refuse to believe that she is a capable enough writer that any subtext that people are now finding in the novels are more than the I-see-what-I've-been-told property. I'm sure if someone influential to any reasonably long series announced one of the characters was really into bestiality, you would begin to view the subject with that in mind, and find things to affirm that, whether they were originally intended to or not.
Also, it's a CHILDREN'S BOOK SERIES. I'm not saying there's anything wrong with teaching children tolerance, but this announcement was obviously made for the older, minus-a-life fans who wanted something juicy to nibble on, as with the encyclopedia that's being planned.