The Air is light. Even eight months after release, it's still one of the top 2-3 lightest 13 inch laptops. I briefly had a 10 inch netbook, and MUCH prefer using the Air because of the 70% larger screen area and un-cramped keyboard. Plus 13 inchers allow you to put two documents side by side, which is indispensable for my student-related research stuff.
Also, I don't find using thin designs for aesthetic purposes to be disturbing. I find it...nice to look at! Maybe not optimal for power-users, but great for non-gaming students or basic business users. And the lighter design is good for me, because I've got two surgically repaired shoulders. But then again, I don't own an Air because it's too expensive, so hopefully the new Macbook will shed some poundage while maintaining a reasonable price.