Kaftan,
United, Delta, TWA and American (probably more) give you lifetime elite status by hitting one million miles. American is the only one that I am aware of that will give you lifetime status with miles earned in any fashion (1mm = lifetime gold, 2mm = lifetime platinum).
TWA's lifetime program will expire as soon as the Aviator's program gets integrated into AAdvantage. No more lifetime status for those folks.
ff