After the announcement of the MacBook Air, all anyone seems to do is compare it to other ultra-portables, or at least other thin laptops (if you're the type to exclude the MBA from the ultra-portable category). But, one thing that is not often mentioned in the lists of specs is what is the monetary value of using OS X vs XP/Vista. That is, how much more are you willing to pay to be using OS X? I, for example, really feel annoyed by Vista, but that's just after using it for less than five hours with boot camp. Time will tell whether it gets more or less annoying as time goes on. At the moment though, the MBA premium seems worth it, since it's a light-ish computer with OS X. But, that's just my preference. What does everyone else think?