I'd go even farther and say that they still are. Honkin' on Bobo from two years ago put them back on the map, and Joe Perry's solo album from last year rocked harder than anything in years.
They're a tour-de-force live, the last vestige of classic stadium rock that's still burning bright, still kicking ass, and still putting on a show one hundred times better than men one third their age.
Perhaps some rock it harder, and maybe others rock it longer, but nobody rocks it better than Aerosmith. And anybody who once did is long since gone or degraded to a shadow of their former selves.