As was previously reported Batman On Film heard from their Chicago sources, where most of TDK and Batman Begins was filmed, that scouting has already begun in the windy city..
"[They] have been out and about in Chicago's Financial District."
While on the set of John Landis’ Burke and Hare, starring Andy Serkis and Simon Pegg, a source over at Moving Image is reporting that one of the crew members (that worked previously with Nolan on Inception and The Dark Knight) has given an update on the progress on Nolan's next Batman movie. Apparently said crew member spoke a little about the set design for Burke And Hare, but...
…he also said sets were either being constructed, or will soon be constructed, for the third Batman, with the possibility of shooting toward the end of the year. He also said that they were coming under budget at the end of The Dark Knight, so they built a whole extra set (possible usage in the third film).
Yeah I know its still a bit of "He said this and I heard that", but coupled with the news from Batman On Film, this could turn out to be legit. Anyway, until we hear anything official from these damn suits, all we can do is speculate right?