I used PCs way back since the 8086 machines and watched Windows appear and grow from 3.11WFW and up. I work in graphics and web design, and have worked on Macs for a long time at work, but always had PCs at home, simply because I was more comfortable with them.
Once OS9 dropped away and I saw some of the UNIX capabilities and robust core features of OSX, I figured it was time to get a mac of my own. I'd been using them at work with pleasure for a long time, and had a feel for the power and ease of use on Macs.
Another thing that annoyed me about PCs (and I'm sure many other people feel this way too) is the huge commitment required to keep it working. I can't tell you how many friends I have whose cases are forever pried open because of all the tinkering under the hood. So much of my career was as a technical support guy, simply because keeping a PC working properly requires so much attention.
I got into computers to work in design, and found my reputation was as a "computer guy" and found most conversations became about how to fix computers, or installing drivers, or virus protection, or some such trick to get the PC working, but never about actual using programs or doing design or using applications or whatever. Even gamers would go on about optimized video drivers and the newest card technology, FPS etc, instead of the game itself.
Mac users rarely if ever talk about all the shoehorning techniques they use to get their machine going, because it just works. If they want to sit down and design, then that's what they do. That's why talking with mac users about design is truly about design and not about "clever" ways to get it to work in the first place. Sure there aren't as many games on the Mac yet, but there is definitely a lot catching up now that they are Intel.
So when I bought my first Mac, a Mac Mini, I thought I would plug it in and tinker around a half hour or so, and then go back to my PC. I checked to see if my files worked etc., and everything did. My MP3s, my video files, my word docs, pretty much EVERYTHING. I didn't get around to plugging my PC back in for a full MONTH, and that was just to get access to more of my files! I since bought a second Mac Mini, the intel version, and have had a mixed computing environment since.
As for building an OSX86 machine, it's amazing how great a machine you can build for very few dollars. You can make a leaping Leopard machine for a fraction of the apple counterpart, and you will find it outperforms windows on the same hardware. Crashes are virtually nonexistent (though not 100% absent) and usability is over the top.
The only problem is, you are back to the same scenario where you have to tinker and "shoehorn" OSX into your PC. You might find the screws to your case are kept off, and you get paranoid about running software update. That being said, once you find a good configuration for OSX86 (for example iPC osx86 or XXX OSx86 installer) with the right install options (and it can be tricky depending on your hardware), you will have a solid machine.
Now that OSX is going 100% Intel with Snow Leopard, I think it will only be a matter of time before Apple starts licensing their OS for other PC manufacturers. The main obstacle that I would agree with is the can of worms that comes out of supporting multiple hardware platforms. How many times have you bought a piece of hardware and read the install instructions that tells you to "continue anyway" despite unsigned drivers?
How much grief will Apple take on if they open themselves up to an open platform? If they at least firmly insist on hardware partners being 100% qualified, then I think they have a shot at remaining the same rock solid platform without performance or quality compromises.
Oh, and of course the other side of it is, the entire legal issue. There is a lawsuit between Apple and Psystar over that very thing, but as a consumer, the most optimistic look you should have about making a "hackintosh" despite the Apple EULA, is to treat is as an experimental platform. No matter how much I love the speed and cost savings of a 3.0GHz C2D machine running OSX, I think the cost of an actual Mac is worth getting rid of the hassles and leaving the case unopened, because it just WORKS.