but this starts me thinking that Apple will just discontinue the Air.
Ding.
Apple needs enough margin on the Macs to make the ongoing development of OSX and related software worthwhile. They don't want/need an entry-level non-retina machine in their line up: it would never compete with the likes of Dell etc. (who can throw together a system from this week's cheapest components safe in the knowledge that it will all work with Windows) but it would almost certainly hit the sales of better (= higher-margin) Macs. This is also why we can't have a basic "xMac" mini-tower with PCIe slots, however nice that would be.
The Air is almost certainly living on borrowed time while the Intel delays (along with fascinating watch strap opportunities) hold back the rumoured new MacBook Pros and/or MacBooks.
The bump to 8GB standard RAM has made the entry-level Air vaguely viable, but its already hard to justify any of the expanded Airs against the 13" rMBP unless you really, really want the marginal improvement in weight & thickness (remember, the 'footprint' of the rMBP is already smaller than the Air). Any new rMBP will probably close that gap.
So, I'd say that the likelihood is either the Air obsoleted by a thinner, lighter version of the rMBP, or by a larger-screened (but maybe lower-powered) version of the MacBook. (Some of the rumors do sound like a choice between MacBook and MacBook Pro). That said, "Air" is just a name and Apple could stick it on any future Mac. (Personally, I'd slim down the 13" rMBP and call it the "MacBook Air", keep the 15" rMBP at its current size, stick the new mobile Xeon in it and call it the "MacBook Pro").
I know its been said exhaustively, but magsafe is one of the single most clever, consumer friendly and useful inventions Apple ever came up with.
OK, I'll play Devil's Advocate here (don't shoot me):
MagSafe 10 years old, in which time battery life has improved from
~4 hours to
~10 hours reducing the need for charging in meetings etc - which is when these 'trip' accidents occur: if your power lead trails across the floor when you are at your regular desk, you're holding it wrong.
The loss will be magnified (pun intended) because the thinner, lighter laptops will be that much easier to flick off a table with a slight tug of the cord.
...ironically, that might be part of the reason why MagSafe is no longer such a great idea: Even my
17" MacBook Pro has been pulled off a table despite MagSafe, and that's a fair lump of a machine. A 12" MacBook is so light that it would probably be flicked off the table with a slight tug of the cord
even with MagSafe - unless Apple made "MagSafe 3" so sensitive that it fell out every time you moved the computer.
Also, there's a bright side to this: MagSafe was proprietary, USB-C is a crossplatform standard. Assuming USB-C takes off in the PC world, you'll be able to charge your future Mac from standard USB-C power supplies, displays and docks.
The problem with the 12" MacBook is that it only has one socket for
everything. I guess the reasoning is the same: the battery life is so good, you'll only need to charge overnight/at home - and back at your desk a USB-C hub is the way to go. (Fine, but I can still see myself having to run a Keynote from a USB stick to a projector in a meeting so, fail) I'd hope that Air/rMBP replacements have more connectivity than that: 2 USB-Cs at a bare minimum. Not that a MagSafe
as well wouldn't be welcome.