That really doesn't make sense, because the IGP isn't the CPU. If Apple really is going to do that, then I'm a bit disappointed. Remember the Keynote slide showing the Apple computers that are 64 bit capable? It was the entire lineup except the mini, which only had a Core Duo chip at the time. There's no sense in promoting 64 bit capability in machine models that won't get a 64 bit kernel.
That doesn't make sense either because Apple doesn't use a big variety of CPUs. For example, the models with the nVidia IGP don't use different kind of CPU as the ones that used a discrete nVidia chip, it's just a different clock speed. Excepting the Air of course, I don't know about that one.
Dont kill the messenger. I am just reporting on what has been done so far. We are close to Snow Leopard going Golden Master, with DVDs made and packaged, yet no support for a 64-bit kernel in their most common machines.
I understand if they made it 32-bit by default to keep driver issues to a minimum, but to not include it when they have done the legwork for their other machines running the same CPUs in most cases boggles my mind, too.