While I purchased a MBA (coming mid February) I have been concerned about the lack of swappable battery given I take long international flights. I stopped by the Apple store today, and did my "airplane battery test." I unplugged the MBA, turned off all wireless and dimmed the screen all the way down to 2-3 notches, and the battery meter said 7:08 hour remaining. Over 7 hours. Wow. Now, I fully understand even in the best case, this would mean 6:30 when actually using it. And of course, on the ground with the screen brightness turned-up and wireless on, I assume I would see between 4-5 hours. But the fact that there is a good shot to use the MBA on cross-country flights gives me hope. Now, don't get me wrong, I would love a swappable battery. But hopefully this is some good news. I'll know in a few weeks.