Honoring Steve's manilla folder is all I can think of at this point. I too thought we were done with the word "Air".
MacBook Air sounds better than MacBook Basic! The word MacBook is just a precursor for a while now, at least from when Steve held the Air up in the air.
Down the line - a year - we might just have the MacBook Air and the MacBook Pro left standing. Thinning the crowd, sounds good.