So, coming to the point of discussion, why doesn't Apple a.k.a Steve Jobs sell the OSX and the Applications without the hardware?? Why doesn't he really beat Microsoft where it really hurts?? Why doesn't he become "Edison" and "improve the world"?? Why is he acting like Karl Marx and Neem Kairolie Baba and only appealing to a niche?? (If you didn't understand the last 2 questions, read this about Steve's life). Here's the short comparison on what are the pros and cons I could think of, if Apple started selling the OSX and applications without the hardware1.) Operating System Market: The OS market is a very huge one and has a lot of money involved. Linux distribution companies are making money from it, although giving it for free!! This shows how much money is at stake. OSX currently holds a small market, but then even getting 5% more than what it currently holds would mean somewhere around 1 billion mark or even more!(source). People have multiple OS installed these days and revenue should be even higher than that. But other than the money involved, the intuitiveness and beauty of OSX is something that will help improve the world. Lot more people will get aesthethic happiness !! ;-)
2.) Hardware Sales: A lot of people say Apple hardware sells because of OSX. I completely disagree with them because just look at an iMac or MacBook. Very few systems can match the beauty of design of the Mac. Apple could easily offer coupons for upgrades or special applications to those who buy Apple hardware. This will make buying Apple hardware even more tempting. Say if 30% people, bought Mac for OSX and don't buy it after OSX is released for any x86 hardware, then Apple looses only 600 million.(source).3.) Technical Aspects: Apple already has an Intel x86 OS running on Mac with Intel chips. So just releasing the package to the shops with a Vista competitive pricing is required. Leopard is also natively 64-bit, which also is an added advantage. So basically Apple could also earn more from the different brandings of 32-bit and 64-bit OS. You could have viruses and malicious code coming in if the market share increases, but I think Apple has the kernel and permission system, good enough to deal with it.
4.) Apple's Server Market: Apple has also a server OS which has some wonderful specialized applications like XSan. The server hardware may be great. But if the server OS is released, other hardware vendors could easily bundle it with their servers. Xserve really doesn't sell much, so Apple really doesn't have much to loose. I think the best part would be if apple could sell support for their OS, just like Red Hat does with RHEL. It really has some money involved!! I couldn't find the dollar numbers, but I know for sure, its quite a lot more than what Apple is earning from selling the Xserve.5.) Market scenario: Vista hasn't worked enough for Microsoft and isn't new enough for a lot of users. Im not say Vista isn't good, but people are happy with XP. In contrast, when people see the OSX, they find it refreshingly new. They would want to buy it!!
6.) Beat the Hackers: There are a lot of people who are already using OSX on their non-Mac x86 computers. When Apple releases OSX, it'll mean no-more-work for these hackers. These hackers will then automatically move to make some newer application softwares ;-) (some optimism from my side maybe), and in turn we'll have lot more applications to choose from.7.) Accessory stuff: Apple could really start selling specialized professional softwares like iLife, Final Cut, Aperture to a larger audience of professionals. Thus bringing more revenue.
I may have missed a few other points (please comment them here and not mail, I'll add them), but I think these are enough for Apple to release OSX without the hardware. Leopard is probably the best time to do it!! The iPhone is doing great and so is the iPod. With the OSX released, it could make Apple grow into a very big giant (it already has the respect, how about some money) of the computer industry. And history says that NEXTSTEP and OpenStep ran on x86 hardware... Will history repeat itself?? Only Steve Jobs or time can answer that!!