Yeah, see? I think this is smart on Apple's part -- quite likely testing the break point between traditional laptops (however small) running full-on OS, and alternate devices running the iOS, touchy, app-dependent architecture. How small is too small, how powerful is powerful enough, etc.
Once they figure this out (and the MBA is a great guinea pig, because it's not a huge sales driver), they can confidently introduce iOS devices below that break point, and more fully-fledged OSX devices above it.
Unless of course the plan is to migrate everything to iOS eventually, in which case nevermind.