Actually, not even Bonds did that (well, technically he did...in 42 at-bats his age 40 season). That new Minny park is really tough on home runs too. Nobody has ever slugged .600 in a qualified season. Williams did it in around 300 at bats as well. Dunno if anybody else ever did in a 300+ AB season, but seriously doubt it. Great season for Thome.
Know who Thome's home run peak looks a lot like? Hank Aaron. If Thome had hit the majors at age 20 also, he would have easily hit 715 too. Wonder if Aaron was on roids. Also interesting about Aaron...his best slugging season (his clearly steroid aided age 37 season btw) is only the 57th best slugging season of all time.