I think you have to step back and take things at face value. It is pretty clear that there aren't a lot of MBAs in the stores. That leaves you with one conclusion: they are outselling the supply. The question is, did Apple underestimate the demand for MBAs and is having trouble producing enough, or did they have to halt production to fix some problem with the MBAs.
Personally, I'm not hearing the type of problems that would require them to halt production. Sure there are the normal little glitches, but by and large the MBA was pretty good out of the box. My opinion is that demand for the MBA is outstripping supply.