smallville will pull in the punters/viewers.
Futurama although being popular too will not win against the "dont need no braincells, lets watch..." smallville community. besides which, smallville always has a "moral to the story", good wins over evil plot line - which more-often than not will override the sex and violence Where-as futurama is plain old well-written humour with obscure references to sex, drugs and violence. Think about it, a robot that smokes and drinks to stay "sober", the occasional words "sex", "ass", "bitch", "crap" etc.
summary: all to do with ratings. as usual im talking b/s so, disregard if you disagree... don't flame me... please...