How is the performance for those ultra low power Intel chips then? Is it as good or better than what's in the current MBA, or could it even eventually end up in a MacBook Pro?
They are better than the i7 I have in my 2011 11" MBA that is my work laptop. They will theoretically be just right for this type of machine.
Sounds cool wish I needed one

. My Mac air from 3 years ago works fine for everything I do on a laptop.
This is exactly the point. Me too, but mine is getting long in the tooth. I'd like to have the newer generation SSD, Bluetooth, Thunderbolt, and Display port technologies (and speeds) but otherwise am very happy with my MBA. This is the machine I am waiting on to upgrade.
I actually called it that Apple would move to a new ultra-thin connection standard in combination with this new rumored machine. I said it could be the new Lightning connector, because of how versatile Apple made it, but this new USB Type C standard fits the bill perfectly.
IMHO this is not a new notebook line, rather this 12" will replace the 11" and the 13" as the NEW form factor for the Air.
Exactly, this is not going to usher in a new notebook line. It is the next generation MBA.
Sounds pretty amazing, but as a rule, I try to avoid the first generation of major updates of Apple products. (Actually not a bad rule for most hardware...)
Take a look at how terrible the first Macbook Air was compared to the second generation, for instance...
Except this isn't the first generation, it is the 3rd generation MBA.
...The issue isn't support the issue is ARM is ****
Not so. I seriously hope Apple makes the move to ARM sooner rather than later, and would wholeheartedly support it. They could unify so many nice features, like TouchID for example, and the only reason you think ARM can't hack it on a laptop platform is because you haven't seen a modern ARM CPU in the category yet. You're basing your judgement on Apple's A-series chips, which are extremely impressive in their native mobile space, blowing everything else that exists out of the water, and that on less cores, less cache, and less RAM than anyone else as well. Obviously they don't compare to Intel's line of core i7 chips for laptops! They aren't meant to either.
Imagine a 64 bit quad core ARM processor with heaps of L1, L2, and L3 cache, 4-8GB of RAM, with a fully optimised custom bus and integrated peripherals, GPU, etc, that is operating on a thermal envelope similar to Intel's Y series chips. If Apple's successful chip designing in the mobile space is any indication, I would put good money on their Laptop & Desktop custom ARM chips to be serious contenders as well, even against Intel.
Unless a developer is using assembler or Intel specific intrinsic functions (and very few people would do that), code built for Intel 32 or 64 bit processors will just compile and run on ARM 32 or 64 bit processors without any change.
This. 99.9% of both consumer and professional software available for OSX now can be one-click recompiled for ARM by developers and redistributed via online channels, especially using the Mac App Store.
Mark this. The next version of OSX after Yosemite will probably be launched alongside a laptop device running a brand new Apple "X"-series ARM chip.