This poll is pretty pointless. The majority of MacBook buyers do not visit MacRumors and do not really have any interest in computing at all. They're students or home users who buy the machines to write essays and listen to music.
We are very much in the minority here, so even though we are sitting at a 51% split in favour of FireWire that's 51% of a very, very small niche.
Yeah, I totally agree with you on this point and new the poll would be very skewed in favor of firewire, but with that in mind it's still pretty impressive that it is about 50/50 on a site like this. I wrote an article on my blog about people making such a big deal about this and linked to this poll for fun (with a disclaimer that the results would probably be skewed in FW's favor) so that was kind of my motivation.