Sure, there'll be a third movie, but will it be the right one?
What I found interesting about this article though is that plainly he's ruminating on a third installment to see if there's an interesting story there.
But, just speaking personally, I never thought we'd get two such fantastic movies at Batman Begins and The Dark Knight. I'm prepared for this to be the peak of Batman movies for quite some time. Meaning, I won't be surprised if Nolan passes, or if, whether he passes or not, the third installment ain't so great.
I just figure it's good karma to be thankful for what you have and not get greedy.