Imagining a newfangled, 12-inch MacBook

If Apple is developing a fanless MacBook, it presents some interesting possibilities.
Will Apple bring out a newfangled, 12-inch MacBook? Only Apple knows, of course, but let's look at some possibilities if it does.

We'll start with the supply-chain-sourced speculation. Several sources, includingNPD DisplaySearch and KGI Securities analyst Ming-Chi Kuo, are anticipating -- and have been for some time -- a 12-inch MacBook.
It's not clear whether it would be a new MacBook Air or an entirely different concept, though it should be noted that most informed, Asia-based speculation to date does not always make a direct reference to the Air.
The latest speculation is the most interesting because it refers to a fanless design. That could imply several things.
Hybrid: Typically, the reason a device maker goes with a fanless design is to put the electronics behind the glass -- not under the keyboard, like typical laptops. Behind-the-glass usually implies a tablet or a hybrid -- the latter along the lines of the Surface Pro 2 or Dell Venue 11 Pro. And note that though it's a hybrid, the Venue 11 Pro can be described (and indeed looks like) a traditional clamshell when the keyboard is attached.
Apple A series processor: It's probably the single most important internal component because it dictates what the design will be. All A series-based designs -- like the iPad Mini Retina, iPad Air, and iPhone 5S -- dissipate relatively little heat and, thus, require no fan. Fanless = very thin and light in the device world. (All current MacBooks use fans.)
That would raise lots of other questions, including: Is it a MacBook (or MacBook-like device) running a future A8 processor? And what operating system would Apple use?
Intel processor: That above scenario, though possible, may be a bit out there for a design that's due "soon." So, let's look at the second fanless possibility. This one on OS X. A version of Intel's Haswell processor can be used in fanless Windows designs, like the HP Spectre 13 x2, a tablet-laptop hybrid. And Apple is very good at working with (forcing?) Intel to develop the most power-efficient processors possible, so it could be an Intel chip that Apple has finessed to run in a fanless device.
And there is always the remote (very?) possibility that Apple will finally adopt the Intel Atom processor (which has been completely redesigned). Atom is a fanless processor.
Display: NPD DisplaySearch said the new MacBook may use a 12-inch 2,304x1,440, putting it into Retina territory. The MacBook Air never went Retina. Apple has put Retina displays only on the pricier MacBook Pro line.
Those are a few quick thoughts after the rumors broke yesterday on Apple blogs. Readers, I'm sure, have different ideas.