Actually it is. The rMB is pretty much the natural progression Apple would take to replace the MBA. Smaller, lighter, retina display. It's pretty much same progression as the cMBP -> rMBP. The only difference is that Apple didn't call the 12" rMB a MacBook Air. Removing the Air moniker for a MBA replacement makes since anyway, since the MBA basically took over the spot of the lineup that the old "MacBook" fulfilled.
Expecting a Retina MBA now is like if back in 2012 Apple released the rMBP as "MacBook Plus" instead of "MacBook Pro with Retina Display" then still expecting a Retina cMBP.![]()
I would agree except that apple's products tend to be built around intel's processor classes.
Macbook, MBA, MBP13 use 5watt 15watt and ~30watt cpus respectively. I think apple will continue to have machines in each of these categories as long as intel keeps making chips in them.