It's no secret that Apple has a history of releasing hardware that requires some tweaking after the fact, and they're certainly not alone in this regard. This update has made a small issue apparently disappear for me, and hopefully will make a big issue disappear for others that have experienced a more significant problem with the Air.
Now I'm interested in determining if this update makes any changes to the battery charging circuit. If there's one thing I could change about the Air, it's the time required to charge the battery. I'm guessing that heat generated by fast charges may be more than the Air can handle, and that results in occasionally absurd charging times. Battery life hasn't been much of an issue for me -- I routinely get four or more hours per full charge, but at times it can take that long to recharge the battery, which is annoying. So far, I haven't noticed any difference.
Overall, I'm pretty much thrilled with my Air. I've used it for just about everything except burning CDs and DVDs, including using a USB-serial adapter to configure routers and switches, do most of my writing, coding, and admin tasks, and have taken it all over the country, tucked in a small shoulder bag that weighs next to nothing.
In fact, one memorable moment came when serial access was required for a VoIP phone switch that was already racked, and had a DB9 female console connector. Since appropriate gender changers or serial cables weren't immediately available, I held the Air in one hand at head-height while using a six-inch USB extension cable to directly connect the USB-serial adapter to the switch, and make the changes I needed. That would have been much more of a problem with a normal laptop.
I'm only a few days in, so further updates as events warrant.