I recently found a pic of my friend holding up my Air that I had just got delivered at the office. She has this look of awe on her at how thin the thing was.
I think Airs are the ideal machine for the majority of the population that just needs to reliably accomplish basic tasks. It's probably the cheapest if amortized over its lifetime.
At least until iPads can do everything laptops can.
I still have that Air. Love that thing.