To take both arguments to their supporting points..

Choose your poison. Either increased smog and pollution from burning more fuel to make more electricity OR an (IMO marginal) increase in pollution in landfills.

Personally, I'll take the latter since there are some pretty strict regulations on what can leach out of a landfill and they're monitored so we know when something's leaking (even if it's late).

Quite frankly, I'm saving money with the CFLs in my house.