Review

I do agree that the design and engineering that went into the MacBook Air is extraordinary, but its certainly a much more specialized product than the standard 13-inch MacBook and wont be as universally useful as that popular system. The biggest compromises, which have been well-documented, come in its connectivity: The MacBook Air finds room for only two USB ports and doesnt include a built-in optical drive, FireWire, Ethernet, or mobile broadband. And like with its other laptops, Apple refuses to outfit the Air with a media-card reader or an expansion card slot. Offsetting its sparse connectivity are genuinely useful new features including new trackpad gesture controls and the ability to wirelessly "borrow" another systems optical drive. What would your life be with two USB ports on your laptop?
Physically, the footprint is not much different than a 13-inch MacBook or MacBook Pro that other members of my household own. However, its the thinness and light weight of this design that brings out the "wow," for those who see it. If you want to use it on your lap in a large chair or sofa, it is simply comfortable. If you need to stop while walking, and stand against a wall and check something very quickly, while it can still be slightly awkward, the light weight makes this possible. Still, Id try not to do this, in fear of dropping the precious unit. You do see some Apple marketing images of people using the device standing up. This would likely be even more comfortable with the 11-inch model.
The reason one would choose this updated 13-inch MacBook Air is simple! This particular model gives you the thinness and light "wow," factors that defined the MacBook Air since its introduction nearly four years ago. However, this model gives you something that was not offered at this price point previously. A nearly fully functional and performing notebook computer. The included 1.86 GHZ Core 2 Duo processor is not a slouch. 2GB of memory is not bad in efficient OS X, and the 256 GB of solid state memory is not only competitive storage capacity to similar notebooks, but yet it is incredibly fast. The slight hit in processor and memory compared to a MacBook Pro is at least partly made up for by the speed of solid state memory. Just check out the boot up time on this device. It boots up fast. Plus, when it sleeps, open it back up, for instant on. Its a new way of experiencing a computer.
This 13-inch model has a higher resolution display than the 13-inch MacBook Pro, so you will fit more of your windows, pictures, etc. on the display. Indeed, it matches the resolution of the stock 15-inch models. What dont you get on this model and do I miss it? Obviously, once again, Superdrive is missing. I do not miss this. I have Superdrive on my desktop computer, and you can always buy the USB Superdrive for less than one hundred dollars, if you want that capability when at your desk. This Air loses the backlit keyboard, one suspects due to the even slimmer and lighter design.

MacBook Air MC504LL/A 13.3-Inch Specifications:

read the full review here

• 13.3-inch LED-backlit glossy widescreen display with a 1440 x 900-pixel resolution
• Up to 7 hours of wireless productivity plus up to 30 days of standby time
• 1.86 GHz Intel Core 2 Duo processor with 6 MB on-chip shared L2 cache and 1066 MHz frontside bus.
• 256 GB flash memory storage
• 2 GB installed RAM (1066 MHz DDR3; supports up to 4 GB)
• NVIDIA GeForce 320M graphics processor (with 256 MB of DDR3 SDRAM shared with main memory) for an outstanding everyday graphics experience.
• Built-in FaceTime camera for video chatting
• Wi-Fi wireless networking (based on 802.11n specification; 802.11a/b/g compatible)
• Bluetooth 2.1 + EDR (Enhanced Data Rate) for connecting with peripherals such as keyboards, mice and cell phones

Buy MacBook Air MC504LL/A from Amazon!
Update:
Apple has released

• MacBook Air MC965LL/A (read the review)
• MacBook Air MC966LL/A (read the review)