well, buy your next machine now. I think you're going to see it disappear from at least certain iMacs at MacWorld (and probably the Mini, too). When USB 3.0 becomes standard, you'll see Firewire disappear entirely across the range - pro Macs included.
Apple has shown a tendency in the Jobs II era to dump things a little early. Floppy drives, onboard SCSI, legacy serial ports...and that was just the iMac, and not even 5 months after the iMac shipped, the blue G3 tower did the same thing.
Also, we need to note: for many folks, the difference between "fast enough" and "faster still" isn't worth an added cost. Adding an Express card slot and paying for a FW chipset would be an added cost.
I agree with you quite often DrFunk, but not this time. USB/Firewire controllers generally come on one chip these days at little or no additional cost over a single purpose chip. This was an arbitrary decision that defies logic. Floppy drives, onboard SCSI, legacy serial ports, all were given up because they added no value. Floppy drives were too small to hold usefull data, SCSI was too expensive and added no real advantage to IDE and later SATA (especially when you look at capacity), and legacy ports really weren't necessary because apple had already moved its peripherals over to firewire and USB. Firewire is still viable and anyone who has used firewire for moving files around realizes how much faster it is than USB, even at the stock 400 speed.
So if there was little or no cost to add Firewire and there is still an advantage to keeping it for many customers, why not keep it? Especially when you do not offer a Mac Pro in the 13" format that includes it?
I don't think this is defensible. This was a decision made by fiat that limits the market for the product. The 13" segment divides into the ultra portable and the small laptop market. Ultra portables have certain tradeoffs that have to be made to achieve the format. The small laptop is about putting as many features as you can into the smaller format. Sony, HP, Dell, Acer, etc. have all been able to keep Express Card and Firewire (even though none of those companies have been huge Firewire supporters), and yet on this, Apple chooses to shortchange the Mac Book. This is just one of those inexplicable things that Apple does every once in a while that doesn't make a helluva lot of sense.
I certainly expect Apple to be one of the first on the USB3 bandwagon, but until that is available, it made no sense to drop Firewire. Even less sense to drop ExpressCard so that you could add it if you really needed it.
To be honest though, I've never really understood the whole differentiation between the MacBook and MacBook Pro. There is nothing wrong with segmenting your market into different lines, but it can be done by differentiating video cards, memory, cpus, etc., rather than crippling the I/O possibilities. Other companies seem to have figured this out, but Apple just hasn't.
With Apple, you have the choice between a mid-priced, but somewhat crippled 13" laptop and very expensive 15" and 17" that have every feature known to man. Yet if you look at Sony, they don't have that artificial limitation. They have 13" laptops that have plenty of features that don't break the bank, they have ultraportables that have some limitations (and carry a premium price), they have lower end 15" + 17" units, then they also have some break the bank models as well. Their segmentation is rational and offers different ways to to segment the market at each price point, rather than just charging more and adding more features as you increase screen size.
I realize that it's working for Apple right now, but I think if they really want more market share, they are going to have to segment a bit more wisely.