The loss of firewire may upset a few college students doing audio/video editing courses and a few pros that prefer the smaller form factor/price of the new MacBook, but the MacBook has always been a consumer orientated device.
As much as you would like to believe these laptops are geared towards students doing video/audio editing, Apple is chasing a much more lucrative and larger demographic- late 20-early 30's, in well paid jobs, that have higher disposable incomes.
Someone here made the comment that the students of today are the pro's of tomorrow: turn them away at the gate and then when they are the pros's, and it is tomorrow, they won't be there for you. GM learned this the hard way with its cars: the majority of the baby boomer generation simply passed up their cars for three decades.
And just what the hell kind of consumer thats looking for a device like the Mac (good for photo/video editing) can afford a $999 anyway? The kind that is willing to shell out to get everything they need in their computer to do what they want to do. Given that now they need to shell out $1500 or more just for the measly firewire port, I can already see some customers just turning way. Mac was beginning to get popular with the masses, people were beginning to consider taking the plunge and buying a computer that costs $400 more than the PC's they used to look at for the sake of getting something good that would last and be usable. Now, Mac has took away the ability to use it outside (unless its a cloudy day or there are enough trees and umbrellas for everyone to sit under), and the ability to do a good video cut with it.
I work for Best Buy. We just began selling Mac's at my store four months ago. Today, we had the unveiling up on the screens in Home Theater. When everyone learned the new Mac's would all have glossy screens and the MacBooks would not have Firewire, of the ten people there two jumped up and down for glee at the new designs. Everyone else grimaced and said something of this nature: "how can Apple make such amateur design flaws?" At which point, the two fanboys screamed daggers at the rest of us for (this is just me summing up what they said) not sucking down everything Steve Jobs says with gusto.
Of the eight potential buyers who weren't enthused about the new MacBooks and MacBook Pros, seven bought right then and there. They did not want to get stuck with a shortage of new MBs and MBPs in the coming weeks, as its been the case the past few years that whenever Mac launches an update the pre-updated product becomes scarce (think iPhone or iPod Touch before the 3G launch).
All I can say is that Mac has plowed into territory unheard of. Making such mistakes. I mean, this isn't even a big deal at the design stage. Its not like they said "well if we want an aluminum case, we have to have a glass screen" or "if we want to offer the MacBook at $999, we have to throw out Firewire." Neither of those mean it has to be this way, you can have a matte screen with an aluminum case and every other feature they unveiled today. You can have Firewire and still launch the computer at $999. Hell, the hardware here isn't vastly more (if at all more) costly than the old hardware, and they definitely didn't incur vast design costs on anything other than the new touchpad.