Evidence for Apple's imminent MacBook Air revamp - well, circumstantial evidence - comes from Amazon.com which has begun emailing customers with the offer of discounts on the current models. Amazon Macbook air ad To be fair, the discounts are small - between five and six per cent off the standard price - and Amazon may simply …
Discounts may be small, but its entirely possible that that 5-6% is all the profit that Amazon make from selling them. If you've ever worked in a retails shop (other than apple) who offeres staff discounts, they almost always exclude apple products.
Apple buyers tend to spend a fair ammount of money on accessories for their iPhone, iPad, iPod, Mac etc, which is where the retails will make their products. Most of these accessories will be costing less than 1/3 of the retail price.