Microsoft are doing the only thing they can do right now, and that's attack the hardware and price.
Let's be honest, Macs are more expensive hardware than most equivalent PCs. There are always cases where the price will come close, but most times PC OEMs can offer much cheaper prices.
That being said, Apple has decided not to compete in that market. Doesn't matter how much they bought the parts for, or what their margins are. Apple as a company has chosen to price their hardware according to what they feel they can sell it for. The market (customers) will determine for Apple whether their decisions are correct or not.
What Microsoft can't do right now is argue Vista vs OS X. They want to run away from Vista and that name as fast as they can. It's tarnished. Doesn't matter whether it works now or not....the bad name and vibe is out there.
So right now their only choice is to hit Apple where they can.....hardware, specs, and price.
Personally, I think it's much more than just the initial cost that justifies buying a computer. I try to look at the overall experience. Afterall, you don't buy a computer to just have it sit on the table.....you have to turn it on and use it. This is where the operating system and applications come into play.
My personally, I love OS X. It's the reason I use a Mac. It's the reason I switched my Mom to a Mac. Plain and simple, I am able to work better and more efficiently in OS X. It's a pleasure to sit down at my desk everyday and use my computer....not a chore.
My mom was fed up with her Vista laptop. I got her a MacBook and she hasn't looked back.
iPhoto vs. Windows Picture Gallery.....no competition there.
Apple Mail vs. Windows Mail.....again, in my opinion Apple wins here.
Screen sharing in iChat and Leopard.....brilliant and seemless. No port forwarding, no configuration. My mom has a question or issue....no need to wait until the next time I see her....or try to walk her through it on the phone. Just have her sign onto iChat and see the situation myself. This also goes for screen sharing between my own Macs. Simple, easy and works everytime.....built right into the OS.
The little things built into OS X that help my productivity are what matter to me.
Time Machine is awesome. Works in the background, no hassle, no fuss, and has saved my ass on a number of occasions. It did exactly what it was designed to do....make backups easy.
Spaces. I develop of my Mac all day long. Spaces has changed the way I work. No longer am I messing around with tons of open windows in my face. Everything is organized accordingly.
Expose. Perfect implementation of window management. Just a simple keypress or mouse shortcut I can see all open windows, or just my current apps open windows.
The overall interface and design of OS X. To me, Aero is UGLY. I mean c'mon, why do I want to see a window behind the current window I'm supposed to be focused on? I think OS X (other than Aqua....man I can't wait for Marble) is beautiful. And when I have to sit on my machine all day long and actually USE it.....it makes me more efficient.
I was a Windows user....still am. But my main machine is a Mac, and the reason....OS X.
Do I want Apple to license OS X to run on any hardware....no not really. I do think OS X benefits from the closed system that it's in. Yes there is a price premium, but me personally, I'm willing to pay for it, in return to get what I feel is a better user experience.
Hopefully for Windows users, Windows 7 increases performance and reliability. Overall, I still think it looks ugly and is way too cluttered and messy.
-Kevin