Apple are starting to make some efforts to start catering for those on a lower budget (e.g. the plastic versions of the iPhone 5) ... but they don't want to start cutting corners and going all cheap because that would risk brand integrity. I suspect we will probably eventually see a re-introduction of a plastic option for Apple laptops (and maybe even desktops, but I suspect they're waiting to see how the desktop game pans out in the industry).
Almost every non technical user I've come across has stayed with Mac once they made the switch. It is fair to assume that most XP hangar-on'ers are of the non technical variety. I feel it's wrong for Apple to start making el-cheapo hardware as this puts it on the path of a race to the bottom. I also feel Apple are missing a golden opportunity in reigning in users who will experience Mac ownership for the first time and probably never go back. Maybe they should offer a price discount to those that hand in a genuine XP license.
Furthermore, with W8 being a supposed flop (metro interface isn't for everyone), Apple should have further seized upon Microsoft's bad marketting of itself.