you guys got it all wrong!
if apple had their way, all of the powermacs would be duals, but IBM would not be able to keep up with production: they would need to make double the ammount of chips for each lower end computer sold. wait until supply is plentiful: THEN, you will see lower end duals. even now, demand of the dual 2GHz machines exceeds supply, forcing apple to delay shipping dates.
remember, apple did this at the beginning of 2001, with the 733 MHz machines. they were single processor, even though they used to have Dual 500MHz g4s before that. Steve explained this by saying "if we made them duals, you'd have to wait 3 months for them to ship because of production speed."
from a marketing perspective, apple has done a surprisingly GOOD job in light of these production issues. the current pricing structure is designed to make people look to the next model up, driving sales towards the dual 2GHz (apple's highest margin machine).
if someone looks at the 1.6, then they check out the 1.8, they will see that it offers far more technologies, for just a little more money. so now, all set to buy the 1.8, they look at the dual 2GHz and realize that they will get more than DOUBLE the performance for just a little money. see how it works?
in any case, as someone pointed out, apple would probably have a contract with IBM that basically says: if apple wants to use IBM's latest and greatest chips, they have to also buy some lower end chips. apple doesn't really want to sell lower end duals: some people have mentioned that the Dual 2GHz has sold 5 times better than the other models. i think that rather than many customers being LOST because of the lack of lower end duals, they have instead shelled out a little more cash and gone for the 2GHz model. given a choice, they would probably paid a little less for a dual 1.8, but from a profit perspective, it's better for apple if the customer buys a 2GHZ dual.
just my thoughts on the matter.
