It's not. Believe me I tired calibrating a billion different ways, in the hope it would make the lines less noticeable. It's a hardware design fault/QC problem.
I concur. I have Rev B SSD with faint lines (9c90), and I have fiddled (admittedly not going nutty) with both default and 2.2 gamma and both exhibit the behavior. I do much prefer the 2.2 setting, and I really do like everything else about the MBA that I have chosen to try and ignore it (refocus my eyes). It is really a funny thing as it does really only seem to happen under certain lighting conditions (at least with mine).
I am disappointed that the new models are exhibiting this as well; however, I am not terribly surprised. I think some folks were being overly exuberant to believe it would be corrected. It really does suck as this issue more than any others (lowish screen resolution and fixed 2GB of RAM -- might just be that to double the number of chips on the mobo would draw too much power/dissipate too much heat or cost too much for their margins
) mars an otherwise fantastic computer.