You have to pay through the teeth to add Applecare. Apple's warranty does go above most warranties though.
Price out a three year warranty on a Lenovo T420 with advanced phone support ($209) and compare to Applecare from BHphoto.com ($190 for Air & MBP13). Granted, the Lenovo is onsite and pure depot coverage only is cheaper, but Applecare with an Apple store nearby is comparable to onsite coverage as you have to schedule with the technician anyway like you schedule w/ Genius bar. Just sayin, yes Applecare costs a bunch of money, but warranty extensions cost a bunch elsewhere too...
You would think that the huge premium over a PC would get you longer than a year right?
Seriously, you can get more warranty if you want to pay for it -- i.e. Applecare.
As to the other part, since you're in the Macbook Air forum, which Window's PC's are you comparing the Macbook Air's to in order to get this "huge premium"?
To compare to Macbook Air's you need to stick with Windows laptops measuring 0.68" thick or thereabouts. With SSD included. Which models are you comparing against?
If you expand out to the Macbook Pro line, you need to stick to Windows notebooks at 1" thickness or less and with a business-class build level. Again, I'm curious as to your particular examples with similar specs (including dimensions, weight, and battery life) that you feel are significantly cheaper.
I'm genuinely curious. If you don't want to clutter the thread, PM me.