I think that Torres has an enviable goalscoring record for someone so young - and with a great team around him it could get even better (just like van Nistelrooy's strike record went up immediately when he moved to PSV...) If you want to compare look how many goals these players scored with the same age like Torres:
Rooney - 132 league apps in first 4 seasons
van Nistelrooy - almost 100 league apps in 4 seasons - in the easiest goalscoring division in the world (Eredivisie) :D
Ibrahimovic - 113 league appearances in 5 seasons
Henry - 113 league apps in 4 seasons
Torres - 134 league apps in 4 seasons
Plus I think that Torres can bring alot more to Liverpool, not just goals.He has strong character, first touch, he is fast also.
Little overrated player, but he can really be excellent, now he is not... When Henry came to Arsenal, who would thought that he is going to be the best EPL player by many...