Sam Oliver, AppleInsider:
Since the debut of the Sandy Bridge MacBook Airs over 4 weeks ago, people familiar with the matter say Apple has been unable to equip its indirect reseller channels with any significant stock of the more popular 13-inch models. [...]
The main reason is price: the 13.3-inch MacBook Air starts at US$1299 and is the cheapest among its rivals.
The ASUS UX31 sports a 13.3-inch display, but isn’t available yet; you’ll need to wait until September. The UX31 is rumored to be priced at about $1500.
Another contender is the newly introduced Sony VAIO Z that weighs in at just 2.57 pounds and 0.6 inches. The 13.3-inch MacBook Air is heavier at 2.96 pounds, but the Z is priced at $2749. At that price you get a 1600×900 display and as far as I know the Z is the only 13.3-inch ultrabook you can equip with with an optional 1920×1080 display. But at more than twice the price of the MacBook Air?
The Samsung Series 9 is another. The 13.3-inch 2.8 pounder starts at $1349. The LCD is limited to just 1366×768 pixels, where the MacBook Air sports 1440×900, for $50 less.
The Lenovo X1 matches the price of the Samsung Series 9 at $1349, but is a bit portly at 3.7 pounds. Another unfortunate match is the limited pixels at 1366×768.
I’ve only focused on a few features like weight, thickness, and pixels, but the 13.3-inch MacBook Air turns out to be the most affordable ultrabook you can buy today. And maybe that’s why demand is so strong.