I had a good look at the latest MacBook and MacBook Pro yesterday and bemoaned to the Apple Store sales representative that Apple no longer fitted any Firewire port to the MacBook and only a Firewire 800 port to the MacBook Pro. For those of us with several portable Firewire 400 only hard drives, this seems like a backward step.
In fact it isn't. Fortunately. The Pro will be the only model to consider in the future, mainly because we use SuperDuper to create bootable back up discs which apparently do not work using the USB port (I haven't tried this but have read that only Firewire drives are bootable).
So, if I upgrade to a MacBook Pro I will need a 400 to 800 adaptor like this one from Sonnet. That's a small price to pay for progress, I suppose, but much smaller than the cost of upgrading some of my PPC-only software.
Meantime I just keep on trucking with my four year old PowerBook!