I lamented over this for a while, but since giving my old 4G 20gb model to a family member, I don't need the firewire support anymore with the nano and 5G 30gb I have now.
My daughter still have a 4G color 20gb model that uses firewire, but it never came with the firewire cable, so she's always used USB to sync with.
Her's came with the USB wall charger, so everything is all good.
I think the removal of firewire was a concern at first, leading some to think the new Intel Macs would see similar firewire cuts, but I think that's been resolved now with all of the newer models having at least one firewire port on them.