OS X will be released to OEM for other computer manafacturers. It's only a matter of time, the right time. Apple has never really marketed itself in the enterprise and has no plans on doing so. Their strategy is home / education / research markets.
When Apple releases OS X to OEM the operating system will gain wider acceptance. Large enterprises will have the ability to evaluate it and even deploy it. With greater acceptance will come increased market share. Many software companies who do not develop for OS X will be forced to do so to compete.
There is a huge backlash brewing against Microsoft. Everyone knows Microsoft is falling apart. They are completely lost as a company. They are all over the map just throwing crap against the wall to see what sticks. They can't deliver. They can't innovate. Their software is sub-standard and over priced. Vista is a joke. The problem is no real alternative has existed -- until now. OS X can do what Linux never will -- make Unix mainstream. As OS X is accepted on a much wider level so will people's interest in Apple and all their other products.
The OEM of OS X will not result in lower Apple hardware sales! Market dynamics are extremely different than the clone days; it will increase Apple hardware sales and exponentially increase OSX market share. Apple makes the best, most beautiful, and most functional computers bar none. That won't change even if the likes of Dell are selling OS X.
Many people buy Windows and PCs because they don't know better. Apple still seems fringe, different, or hard. When OS X starts showing up at their work and is accepted over Windows they will want it for their home computer. When they look at an iMac and compare it to some black and grey Dell, the iMac will be going home. Apple will provide superior computers and a superior computing and computing buying experiance for their target market. Apple's hardware sales will thrive.
Apple's overall market share will jump dramatically into the 30% - 40% range quicly and Microsoft will collapse, open source, break up, or actually innovate for a change.
It's coming. Apple is leading a revolution in computing and no one really believes it yet. OS X is so far superior to Windows in every way that matters -- and everyone knows it. Dell, HP, and others are desperate to sell it. Pressure will force Jobs to capitulate, if he's even the reason it hasn't happened yet. I personally think Steve Jobs has been waiting for the oppertune time to make the move; and I feel it's getting very close. Apple's share holders will start demanding it. The market will be demanding it to keep that astronomically high stock price shooting upward. Pressure is indeed growing.
Apple is changing, growing, diversifying, maturing, but that doesn't mean they will stop selling computers; far from it, they will sell more computers then they ever have and much more. Your precious Mac experiance will not go away; only the crappy Microsoft experiance will.
Apple will become the undisputed leader in technology!
It's going to happen.
(assuming I have a say of course lol). 
