Scottsdale, if you asked me if Apple was going to change the size of the MacBook Air in terms of screen size I'd tell you no. I just see the smaller MacBook Air as being more likely then then a larger MacBook Air given the market for the larger MacBook Air just doesn't seem to exist.
There are plenty who are in the same boat as you in terms of how you use your MacBook Air, but I think it's clear that in the end you are in the minority. Even you make arguments that seem to go against the idea of a larger MacBook Air, specifically the original MacBook Air. At its current price point the MacBook Air is justifiable, at 15" it becomes significantly less portable, but at the same time in the form factor of the MacBook Air the specs would become be rather expensive, similar to the original MacBook Air.
As for the tablet, I don't know how secondary it can be. The lack of a physical keyboard is going to make it difficult to do a lot of things, particularly word processing. I'm still not sure you would hold the device if you had to type something longer then 50 words, do you lie it on a table and lean over the device? I see the tablet as more of a novelty/media device then anything else, but that might just be me. The MacBook Air has clearly made itself a primary machine for some users, I'm just not sure that it is most users. I can't imagine many that would find a Tablet fitting all of their needs.
I think we both agree that the MacBook Air needs an upgrade in power, not screen size. I however, find the lackluster sale of MacBook Air's competitors evidence that the MacBook Air may still be winning the competition.
Well, I think the 13" MBA could get a smaller footprint, weigh less, and be thinner, but I think it stays with 13" display and low voltage not ULV. If there's an addition of a 15" display, it wouldn't be much bigger overall than the current 13" MBA. It would just have a bigger display and more space for cooling and battery power. Many people do want a MacBook Pro that uses the MBA design and don't care about the optical drive. I am talking about two completely different things here... one a MacBook Air update and two an addition to the MBA form factor with a 15" display. I wouldn't say Apple shouldn't do either!
I think you will be shocked at how the tablet becomes a transformation to the way everyone works and uses computers. I cannot wait for a tablet, but I plan to own a MacBook Air too. Interestingly, I see the tablet as a reason to get rid of my iPhone. I want to go back to a basic phone that handles all of my calls. My tablet can do everything else.
My lifestyle revolves around being at places not being out all the time. When I go out to dinner, I need to focus on my family and friends. When I am in the yard or bathroom, I will use the tablet. When I am traveling and am in an airport, I will use the tablet but have my MBA for need when actually on the plane. When I am at client offices, I will use the tablet for personal communications and MBA for certain tasks. When I am out everywhere, I will have the tablet as a communications device, scheduler, book replacement, paper replacement, magazine replacement, text messaging, and etc. When I go to my parents house, I will just take my tablet. When I am in the car, I will use the tablet if I need directions or to find a restaurant.
I think the tablet will go everywhere with people. Sure it's bigger than something that can fit in your pocket, but people carry around planners and notebooks, purses, and etc all the time that are the same size or bigger. Just think about students who will not have to carry all their books in their bag as the tablet can hold them all. Or a student who no longer wastes paper to take his/her own notes.
I really think the smartphone has gone too small and provides a crappy experience to the user. I think the MBA is too big and provides a crappy experience as a secondary communications/web surfing device and portable device. I think the tablet takes over all of that.
The MBA is just used as a real computer by those who want premium but don't need professional grade computing power. The MBA should definitely be focused as the primary Mac.
I think those that are using the MBA as a secondary Mac were not the initial target market. It wasn't meant to be sold for $999 to someone wanting to check their email and do light surfing. Not at its original price, that was to be a primary Mac for a market willing to spend more money for performance in a lightweight and thin package that is essential to be ubercool!