LOL! I think it was on her website last year sometime that she actually went into a Harry Potter chat room and gave out her theories about what was going to happen and no one believed her! She told them that she was JK Rowling and again no one believed her. So she gave up and then started talking about Sponge Bob Squarepants.
ES: I know Dumbledore likes to see the good in people but he seems trusting almost to the point of recklessness sometimes.
[Laughter] Yes, I would agree. I would agree.
ES: How can someone so -
JKR: Intelligent -
ES: be so blind with regard to certain things?
JKR: Well, there is information on that to come, in seven. But I would say that I think it has been demonstrated, particularly in books five and six that immense brainpower does not protect you from emotional mistakes and I think Dumbledore really exemplifies that. In fact, I would tend to think that being very, very intelligent might create some problems and it has done for Dumbledore, because his wisdom has isolated him, and I think you can see that in the books, because where is his equal, where is his confidante, where is his partner? He has none of those things. He’s always the one who gives, he’s always the one who has the insight and has the knowledge. So I think that, while I ask the reader to accept that McGonagall is a very worthy second in command, she is not an equal. You have a slightly circuitous answer, but I can't get much closer than that.
She also give a very interesting answer as to why Voldemort gave Lily a chance to live. Looks like we may be hearing more about that in the future.