And that doesn't even address the heat issues that will arise when you toss a high clock quad core, heaps of RAM, and a dedicated GPU into a tiny box a little larger then the size of a DVD case, which means more fans, which means even more power draw and less battery life. Nor the fact that such a configuration would be more for high-end gaming, not casual web surfing and e-mail and so forth which is what netbooks are essentially designed for- just because the Air happens to be a mac product doesn't mean it somehow should exceed that inbuilt design consideration and become a gaming PC.
You don't need a quad core to surf. You don't need a dedicated graphics card to watch youtube videos, and you don't need gobs of RAM to do either of those things; and they all draw more power which takes away from one of the huge advantages of a netbook, which is that they usually last a lot longer on a charge then a standard laptop (given both are relatively new) my laptop lasts about two and a half to three hours; netbooks often achieve over 5 hours of ontime per charge.
It's a game of tradeoffs. If you want a "gaming machine" you either buy or build a proper desktop machine for that purpose or fool yourself into thinking that dropping several thousand dollars on a gaming laptop is worth being able to play the absolute newest games for a few months. If you want a extremely portable, long battery life device for checking your e-mail and browsing, you get a netbook. You can't have both*.
* In the same machine. You can have a separate desktop machine for gaming and a netbook, so you can have "both" in that sense
