Well, being no fan of conspiracy speculations in general, I'm now intrigued.
I am also a not a fan of conspiracy theories simply because they almost always turn out to be false
Software side:
A popularization of Apple OS would mean a push towards UNIX based systems. It should hurt Microsoft and help the Linux/GNU movement.
It would hurt Microsoft, sure, but not really. THey are far too entrenched to make a difference. This case isn't so much about popularity of the Mac OS - just its legal usage and sale by a third party. People are already aware of OSX - Apple's sales prove this. Apple also already supports Unix and open source development the moment that they announced that OSX was unix based. That was years ago
Virtualization software firms like VMware would stand to gain tremendously in both OLD and NEW PC markets. Who wouldn't want to try putting OSX on their currently under-used pcs with a more stable Apple OS?
Except VMware has several products already that are Linux based as well as Windows based. Their Fusion product line is still quite new. Virtualization has been around for a long time and its starting to have value on the server side of things where network admins are already aware of Linux and have been running it on their servers for years. IBM is a big proponent of Linux servers as well. There is a catch - under powered systems aren't going to virtualize any system real well (except for small footprint systems). Desktop operating systems like Windows and Mac OS require more powerful hardware to run them with each iteration. Servers are well equipped to handle that load since they are really powerful machines (and are not run like desktops are). Its just cheaper to buy new hardware to run modern operating systems.
VMware is growing in popularity, but outside of Fusion (mac product) their strength is server products where Windows and Linux already dominate - Linux purely because of the lack of licensing.
Other software companies that specialize in OSX software will also stand to gain with mass distribution.
If they wanted to gain mass distribution like you talk about, it would make more sense (in my mind) to develop versions for other well established operating systems than to hope for rapid acceptance of an OS with around 10 percent market share already. Heck, thats why Apple developed iTunes for Windows - they knew that the iPods popularity alone wouldn't drive people to Macs en mass - if Apple believed that, they would have kept the whole ecosystem on the Mac - which would have inhibited adoption.
Hardware Side:
HP, Dell, Sony and the like would love a hearty bite not only of Apple's not insignificant marketshare, but also the overall PC market. If Apple were to authorize clones, one would expect Apple to license to big boys like HP or Dell rather than eMachines.
And destroy their own hardware business like what happened in the 90's? THe hardware makers you quote compete primarily on price and the lowest common denominator. Hardware profits for these guys are razor thin. Thats why they resell Windows. Microsoft doesn't have a hardware division that they have to worry about undercutting and the hardware vendors won;t get far selling computers without operating systems and relying on people to buy Windows afterwards. Most people do not buy Windows. They get whatever is currently offered by the OEM's and they tend to upgrade when they get a new computer. Most of these people buy the cheapest computer they can. Apple already knows that trying to compete in this area is a fools errand when you have a hardware division.
The reason that Apple does not sell cheap computers is the same on that BMW doesn't price their cars like Toyota does. By happen chance their market share is about the same.
Steve Jobs on market share:
We would like to see our market share grow," Steve Jobs, Apple's chief executive, admitted to The Independent on Sunday last week at the Apple Expo held in Paris. But he argued: "Our strategy is to innovate. We are the innovator of the industry. Most of our competitors try to copy us. Our strategy has worked really well for us."
Others agree. "Apple is not going to be a vendor that can buy market share, or one that can easily enter new markets," suggests Ranjit Atwal, PC industry analyst at the research firm Gartner. "It is concentrating on its existing markets, and on making sure its average selling price and revenues make it viable. Volume isn't its game."
[...]
"If you went to BMW and asked them why they don't outsell the Ford Taurus, they would say they don't want to make that sort of car," says Mr Jobs. "Apple has 25 million customers around the world, and our goal is to give them the best personal computer that we can, with the best operating system and some of the best applications."
In either hard/software case, the big wigs in these companies would have to be pretty insane to pull this!
Not if they excepted not to get caught or hoped for a settlement of some kind. Apparently Apple wants to go for the jugular.
Alright, while I'm at it, how about PRE-EMPTIVE SELF-DEFENSE? That Apple could be behind a bogus company that Apple "has" to go after. The bogus company then resorts to the lamest defenses that Apple could easily defeat, hence establishing case laws to immunize Apple from future attempts at robbing Apple OS by others. At the same time, Apple could test out waters and see how the market responds to "Psystar products".
1) People have wanted Apple to clone for years
2) Why would Apple want to waste the courts time in identifying psystars backers if they know who they are. The minute the answer becomes public, the court is not going to be happy.
3) Supposing this is true, why is Apple trying to keep a lawsuit going so long even to the effect of suing themselves. Why not end the case from day one and have a public settlement that benefits Apple?
4) You seem to forget that Apple's last legal cloning era was a disaster for Apple. Why test the waters that Jobs was very vocal about not testing a decade ago when he killed cloning? Why do it with a company that would be breaking other laws that trademark infringement that would invalidate market interest studies and a poor cloning method. Why do it in a way that angers the open source community?
You are talking about a high risk scenario that would require complicity with a lot of people at Apple. This is contrary with a company that has millions of people that pay attention to Apple every day. A company that despite its best intentions, has leaks from people willing to break NDA on this very forum and others. Not to mention the person squealing would have an exclusive and would be rich. With a company so rich with speculation about its actions, you would think we would have heard something from people with well placed sources like Kevin Rose or what not - instead we have tons of people who are criticizing Psystar. You are talking about a secret that is next to impossible to keep.
Which is easier to believe - An Apple conspiracy, or a company that sees itself with little to loose and is fighting a loosing battle terribly. Maybe Psystar has support. I doubt its a mainstream company like Dell or Microsoft, but its possible.
ETA: We also have to remember that Apple has largely ignored the home brew aftermarket hackers and the OSX86 project. THe reason is twofold: They aren't selling anything, and they are not worth going after. The minute that there is a commercial company involved? Apple starts suing. Exactly what one would expect of a company like Apple. You don't see Nintendo legally suing homebrew game makers or Sony suing PSP hackers - they just change the system and not support them.