I don't think you need to worry about that ever happening. I am interested in what exactly about that scenario is "scarier than the world we live in now?" Personally I like choice and the biggest barrier to choice for the average buyer is the OEM monopoly Microsoft maintains with assemblers like DELL. It would be interesting to see a vibrant market of Linux machine sellers so buyers do not have to pay the Microsoft tax or build their own. From my experience this is how the market breaks down: most businesses that are tied to Windows software, IT, etc. do fine with XP or even 98, most home users would be better off with Mac OS X. Now before someone chimes in with the usual "just install anti-virus, don't download porn or P2P or click on email attachments and Windows is GREAT" reply, I've heard it before and I disagree.
Added: and about that hush-hush mentality? are you talking about Microsoft's willingness to blather on and on about vaporware like Cairo and Surfaces whereas Apple doesn't? what intellectual property did they take over? and what is with that "my lifestyle is better than yours attitude" comment?
Sorry, I don't know how to quote multiple people, so I'll go with this reply and try to generalize from here. My "scarier than now" statement refers, obviously, not to the current state of the world in general (vis a vis oil, Iraq and a bunch of can of worms I won't touch with a ten foot pole), but with the state of the computing world. I should have been more clear.
What I mean is this: 1) hush hush mentality - before the switch to Intel, Apple was extremely secretive on their road map for technological advancement. They still are, but with Intel issuing press reports every other week, it seems, the cat is pretty much out of the bag. Why is being secretive a problem? Well, if I know what is coming up in the horizon, I have a choice. I don't mean that I should sit on the fence forever waiting for the next greatest and bestest (tm), but that at least I have a choice to do that, if I want. I'm sure every mac customer has been burned at one time or another by a new product coming up right after they bought something (iphone price drop, while not directly comparable, is indicative, I suppose, by the amount of negative feedback on that thread).
As for MS vaporware, it doesn't really affect me, I guess. I'm not here defending MS, I have enough bones to pick with them to do that

The type of vaporware that really bugs me is the HTC Omni...I was so waiting for that phone
2) appropriate other people's IP. OK, maybe a bit of a low blow. What I mean is that everyone in the tech biz takes things from others. MS, Apple, everyone does this. However, Apple has done is a bunch of times, and the fanboy mentality is to give them a free pass, whereas is MS does it, it is a deadly sin. Sure, it is a matter of perspective, a preference for your side (that wasn't on the strike zone, but the ref called it a strike). But, going back to the iPhone as an example (I guess one of the more recent IP issues), it takes a mighty big ego (or guts) to go ahead and declare the name of your product knowing that it is already taken, since you're in negotiations over the use of said name, and fight over it. All is fair in love and war, and business is just a more polite form of war, I guess.
Further back in the thread there was also mention of Konfabulator; we also all know that different computing "desktops" has been in existence at least a decade and a half (true, Apple didn't "take" this IP, but they advertise it like they invented it), look and feel ideas taken from Vista (not many, but enough hints here and there - coverflow is a nice way of giving quick previews, but Vista has their own way already, etc.).
3) lifestyle - Look, I don't know about you guys, but I like maybe 10% of those "I'm a mac" ads, really don't like the way Apple hypes up their "geniuses" (goodness, I've asked simple questions like "Does OSX support Netware/Novell standard for networking?" only to be given a blank stare in return - true, I had to know so that I could integrate my first mac in my network, since we all know that XP has security holes the size of Kansas), etc. I don't want to be Justin Long. I don't want the black turtleneck. I don't really want all the associated baggage that Apple's marketing division keeps trying to sell. Apple has great design, great hardware, a fantastic OS (but not bulletproof...it crashed on me more ways than I can count, hate the beach ball as much as the blue screen of death, which to tell the truth, I haven't seen is years, etc.). Call it a matter of taste, but they should try selling their hardware on those points, not as a lifestyle. Anyone watching Apple ads know that they are pushing a lifestyle beyond their products. It makes sense on a marketing sense - something that MS has not caught on - but nonetheless, the method can backfire if the lifestyle being proposed is not what the customer wants. This customer likes the hardware, not the lifestyle. My choice.
Take all these together, and imagine: Apple owns market share similar to MS has now. You walk down to your local Best Buy, you only see what, 4 or 5 choices in terms of form factor when it comes to computers. Intel is totally on Apple's pocket, so they won't announce their technology road map as clearly, so you don't know whether the newest and greatest mac every build is coming out tomorrow or not. You don't have many options in configuring your hardware; you can't easily change your HD in the laptop, no separate GPU, etc. If you don't agree with their design choices, you're stuck. There is a small market for Linux users who feverishly work to try to get specs and information on hardware components, but they are constantly being dogged by Apple attorneys, and since they own 93% of the market, they have a HUGE legal team and budget. You try to install a new OS in a partition on your mac? The next update will "brick" your computer.
Exaggeration? Yeah, I know, but there is truth, too.
Don't get me wrong, I really do think Apple makes good stuff - I own a bunch of their computers and an iPod. Are they the be all and end all that a lot of mac fanatics claim? Not by a mile. Is Leopard going to be the greatest OS ever? Heck no - consider that every time a new 10.X revision comes out, every fanatic claims that this one is the mostest, bestest, and that the previous one pales by comparison. I think a poster even went as far as saying (I might be wrong here) that after seeing the demo video, he/she thought that Tiger looked ugly in comparison.
Hope I clarified myself (probably not...it's getting late). Sorry for some of the hyperbole I used, I am just trying to illustrate my position. Moreover, I'm sure I must have made a factual error here and there, so please feel free to point it out to me, and I'll take that in consideration.
Now I'm off to watch Ninja Warrior with my kids...I know, to each his own

Horrible show, but horribly entertaining
