Apple's Expresscard slot will take cards which can offer *two* Firewire800 ports.
It boils down to (1) Apple using vanilla Intel hardware (w/ Intel having no interest in Firewire) and (2) the ability to add features for those who need it, while keeping costs down (as we see with Apple's removal of an internal dial-up modem).
Though the removal of a dialup modem is rather timely, though, much as the removal of a floppy drive on the Macintosh was.
I only hope that someone comes out with a FireWire 800 ExpressCard/34 thingy.