As an interesting side note, China is actually considering adapting its "one child" policy to a two children policy. If that were to happen you would see a quick rise in the planets population within two to three years.
I agree that population isn't necessarily the issue, it is just resource consumption. I recently drove across Texas and I can tell you that the population of Texas could quadruple in twenty five years and there would be plenty of land to support the people in terms of space (that is, of course, assuming they don't all move to a handful of major cities). For that population to be sustainable, however, there would have to be considerable advances in agriculture and energy.