I have been traveling, and so haven't been able to note this until now, but Harold Camping has officially rationalized, as predicted by cognitive dissonance/motivated reasoning theory. He has reinterpreted May 21 as a mere "spiritual" rapture, and still affirms that the world will really end on October 21. The New York Times has a quotation on the thought process, which is textbook:
“I can tell you very candidly that when May 21 came and went it was a very difficult time for me, a very difficult time,” said Mr. Camping, 89, a former civil engineer. “I was truly wondering what is going on. In my mind, I went back through all of the promises God has made, all of the proofs, all of the signs and everything was fitting perfectly, so what in the world happened? I really was praying and praying and praying, oh Lord, what happened?”
He wasn't just praying--by going over all of this after a jarring shock, it sounds like he was restrengthening the convictions he already had, and in which he had invested so much. And thus his conclusion that May 21 was just an "invisible judgement day" should come as no surprise to us. In fact, it was probably the most obvious rationalization Camping could come up with.