I know some are saying smaller is not very functional and trade off on functionality.
Are you folks forgetting the original mac was only 8-10inches wide? The powerbook duos with their great following was 9-10inches? A lot of the 12inch powerbook? How about ipod nanos versus ipod touch? Sure a touch is bigger but then why sell a nano?! Hell, the iPad is only 8inches and look how people responded. We've had products that were small and still found them all useful. Resolution is so good nowadays, that small doesn't mean crappy, look wise.
This is the category of ultra portables. This isn't raw power at best. This isn't everything under the hood (just thinner). We can all hope they will and they probably would if they can (for the price they believe is worth doing). This is a kick-ass netbook (cause it sure isn't a kickass Macbook Pro nor a cheap student alternative yet).
This is for the Sales Presenters that use powerpoint. The Finance executive that uses excel, the university Prof travelling room to room, and, maybe the student that isn't living the poor life of a student. People that are on the go and travel light.
I see the need for some that are satisfied with a 13 inch. I see the need to be more portable like an 11 inch (cause despite being thin, it currently is still a bulky footprint). Have you tried using an Air on a plane versus a netbook? Finally I understand those that want a bigger screen but not the weight and think that they are the most unfortunate of all our hopes (cause their numbers are probably very small and thus Apple may not pay attention to).
The ultimate question is will Apple give the Air another round of innovation? Did they make money off of this R&D investment. We all are waiting but is the Air gonna keep being a prestige product or will it be a forever speedbump and dropped like a cube. I hope the Air once again becomes the testing ground for new features that'll later get added to the others (should it work). It'll mean that the AIR is the game changer and remains the ultimate prototype.