I recently chronicled my adventures building and using a homebuilt Mac. Now it's time to step back and opine on how I think homebuilt Macs impact Apple's business...
The first question to ask is whether or not Apple should fear the impact these homebuilt Mac enthusiasts may have on their business. Given that one has to start with a collection of parts, assemble those parts into a computer, then work quite diligently to make that computer an OS X-enabled machine, my general answer is "no," Apple need not fear the hobbyist builders.
True, I spent only US$982 to build a powerful Quad-core machine...but I also spent a large number of hours searching for and buying the parts, assembling the machine, and making it all work. If you add in the value of my time, it's clear that I would've been much better off (financially) just buying a nice iMac and calling it done. Also consider that the finished machine has not one but many warranties, and that any hardware issues may mean dealing with multiple vendors.
As long as building your own Mac requires literally building your own Mac, I don't think Apple has anything to fear--hobbyists and tinkerers may choose to build their own machines, but this is clearly nothing that will have any sort of impact on Apple's quarterly sales. There just aren't that many people out there willing to go all of the effort required to build and maintain a do-it-yourself-Mac to have a real bottom-line impact on Apple. (If Psystar's pre-built Mac clone business survives its probably-imminent legal challenge, then that may be a different story.)
So if the community isn't going to have a tremendous negative impact on Apple, what, if anything, should Apple do regarding these homebuilt Mac enthusiasts?
One approach--which appears to be the approach Apple's taken thus far--is to simply ignore these hobbyist hackers. Since there's no real measurable impact on Apple, fighting the hobbyists may be more trouble than it's worth. What evidence do we have to support the theory that Apple is ignoring this segment thus far? For one, there's been no apparent effort to remove the osx86 project web site, which is the defacto source for information on running OS X on generic PCs.
Another reason to ignore the homebuilders is that, in the long run, in fact, this group of users may actually help increase Apple's hardware sales--people who build their own Mac may then decide they're tired of the work required to keep up with system updates, for instance, and decide to purchase a real Mac. Or perhaps they'll tell their less-technically-inclined friends about the benefits of OS X, and recommend that they purchase an iMac or other Apple product for their next machine.
Alternatively, Apple could embrace the homebuilt community...but the question would be how. Would that be a new version of OS X that doesn't restrict installation to an Apple-labeled computer? An actual line of "Mac Lite" machines that are basically motherboards and generic PC parts? Sanctioning a few combinations of motherboards and CPUs for people to use as a basis for building their own machines? Something else entirely?