I think you are very short-sighted...
Like any other product that is new on the market, it might start out being a bit more expensive than most people are willing to pay for it. However, once the product is in the market for a decent period of time, and the volume of sales starts picking up, the price of the product will be reduced, and then, it becomes more affordable for the masses, and in due time, it won't be any different from the core-2 or the i-series in pricing, and we'll be at a point where ultrabooks ecosystem won't be much different from what the market is now with the "standard" PCs. And so, the ultrabooks will be the standard, and the Mac Air won't be seen as such a big deal, and we'll be looking for the next big thing in PCs (or Macs). The more things change the more they remain the same.
Low profit margins is something that the PC makers have been putting up with for more than a decade now, and it won't be much different in the coming years. Apple can charge more for its products because they have a built-in clientele which is willing to pay more for "perceived" better quality and because of their allegiance to Apple. There is no allegiance in the regular PC market, and people could not care less about where their next PC is coming from. They just want something that does the job, does it well, works with all or most applications, and wont bust their budgets. Apple doesn't have to worry about such worldly things, and they can name their own price and people will be lined up for miles to pay more.
In the end, which won't be long in coming, the PC market will be full of PC ultrabooks, and this current discussion will have been just another silly blogger needing to create a click-bait entry to "earn" his salary.
