[VivaLFuego]

^The only stats I've seen are YTD through October - so it's possible O'Hare would still finish in the #2 spot for the year, but barely (because of the air travel peak during the winter holiday).

That said, it's otherwise a reflection of the broader economy and, as Rail points out, the big airlines trimming capacity dramatically (which in turn would somewhat raise ticket prices and provide an additional dampening of quantity demanded). Given the Delta/Northwest merger it's not surprising that Atlanta didn't see much of a hit - maybe someone else can confirm but I would assume the combination would result in reduced capacity out of the lesser hubs like Memphis and Cincinnati and consolidation of operations through Atlanta.

How did some other hubs like DFW, DEN, or LAS fare?