Just a couple of observations...
The "buttonless" trackpad refered to most likely refers to a new design that omits the physical button actuator assembly, allowing the trackpad unit itself to become considerably thinner (relative to current thickness of course). It is highly unlikely that the end user experience will change at all. Everyone will still have the option for click to click, as well as tap to click. The click will be triggered by a pressure sensor instead of a spring loaded physical actuator - that's all, so nobody needs to get their panties in a bunch over it.
The fanless design will include air movement structures within the base that naturally move air efficiently according to temperature chsnges within the enclosure. The machine will most likely use a y-series Broadwell chip that is already designed to be fanless, and is the follow-up to the y-series Haswell chip that is already available. It will provide gains in battery life with only very modest performance improvements over the current MBA line, but most likely with the top end Broadwell integrated graphics so this will improve.
My only major concern is the connectivity the machine will have. This may be the first laptop without standard USB. We may find ourselves in a situation where the new 3.1 micro USB connector is used, or even several lightning connector ports requiring an adapter, as well as possibly a new MagSafe standard (though now that I think about it, MagSafe 2 is pretty thin)...and what about Thunderbolt?? The base of this machine is going to most likely be as thin as an iPad Air, with the screen flip up being considerably thinner than that.
It is going to be a work of industrial and technological art, and I have no worries about the performance of the machine, but I hope the connectivity is not further sacrificed than on the already slightly limited 11" Air...
Thanks you for your l observations That was excellent!