I would have cut firewire on the lower-end laptops also. Very small number of people use it... cost reduction is more important for Apple's current strategy of converting low-end PC laptop users to apple... it's the $ sweatspot.
Firewire is already dead in the consumer markets... it's really as simple at that. USB 2.0 won several years ago.
FWIW, my Sony A1U HDV prosumer camera is Firewire only, but I would never edit HD on a lower-end MacBook.
Except your argument fails, since Apple isn't passing on the cost reduction to it's customers. They are clearly just using this as a means to push people up to MacBook Pro.
To the people claiming that "FireWire is dead, USB is the future" or that "it doesn't belong in a consumer laptop":
It is not only professionals that use these tools. I myself am a hobby musician (as I spend most of my time studying computer science) and I have neither the need nor the budget for a MBP. But if you're going to do music, you're going to need at least a basic sound card to hook your stuff into. And if you need a sound card, you need FireWire, since USB for streaming audio is a no no. There are virtually no good USB sound cards on the market and the ones that do exist are terrible. Additionally, FireWire 400 is still faster in practice than any USB variant out there. That's not the characteristic of a "legacy" product, now is it?
I was on the edge of buying my first Mac (actually I've been through three MB refunds due to case and screen issues, but that's a different story