It's too expensive. No surprise there: Apple technology is generally quite expensive at launch. The SSD version of the MacBook Air, however, is particularly expensive: It starts at over $3000. Yikes.
It doesn't utilize next-generation Intel chip technology. Though Jobs brought his new lap dog, Intel CEO Paul Otellini, out on stage yet again this year, talking up how the two companies worked together to pull off yet another technological miracle, the chip in the MacBook Air is just a smaller version of last year's less efficient 65nm chips, and not this year's 45nm design. George Ou has more about this decision.
The battery isn't removable. Read that again. Check the MacBook Air tech specs page to verify it. Yep. That's right: You can't even cart two batteries with you when you travel, or upgrade a failing battery yourself. In this way, the MacBook Air is really a Frankenstein-like middle ground between a true notebook and an iPhone smart phone. As Steven Parker notes over at Neowin, what's going to happen to MacBook Air users when they run out of power less than half-way across the Atlantic? I hope they brought a paperback with them. Or a real computer.
There's no Ethernet. The MacBook Air comes with no built-in Ethernet port, which is just astonishing given how unsafe even secure wireless networks are today. While you can purchase a USB-based Ethernet adapter for $29, that adapter will then occupying the one and only USB port on the device.
Yet another power adapter. Yep, Apple has introduced yet another version of its MacBook/MacBook Pro power adapter in order to accommodate the thinner-than-necessary (see below) MacBook Air. Hope you weren't intending to reuse any of your existing equipment.
It's thin to no good end. While there are already a number of ultra-portable machines in the MacBook Air's weight class (3 pounds), most of them exceed Apple's device in ways that are meaningful. They have Ethernet ports, for example. More than one USB port. A docking station for a hardware "slice" that adds more battery and an optical drive. And so on. With the MacBook Air, less really is less, and in this case at least, Apple's (Jobs') penchant for tiny, elegant hardware is getting in the way of functionality in a way that makes the product inherently less useful to users. This device swings way too far into "form over function" territory.
Overall, what this says to me is that the MacBook Air is a must-miss, the portable version of the G4 Cube that flopped almost a decade ago. I have little doubt that Apple will improve this design over the years with a pop-out Ethernet port and other improvements, and will move Air features like the multi-touch track pad (and likely the overall swoopy design) to its more mainstream MacBook and MacBook Pro notebooks. But Gen 1 is a miss. Avoid it.