I just wrote up a post on how the motherboard has no room, then i went to get sample pictures to compare white to unibody motherboards, and i ended up deleting the post, because the white macbook really doesnt have any more room on the motherboard than what the unibody has.
The security port on the white macbook is further along the side, closer to the front to make a little more room but the size of the motherboard is about the same
Apple made a decision to leave firewire out of it, but hey, i dont use it and never have so i dont care. Id like some gtx260s in SLI in there though but thats not happening either