Meander to Marco.org and read Marco Arment’s excellent post titled, “The new MacBook Air“:
The base 13â€ model at $1299 is compelling.
For all configurations, I highly suggest the 4 GB built-to-order RAM option for the extra $100. You canâ€™t upgrade the RAM later. Itâ€™s permanently mounted, like the first Air. The original Airâ€™s 2 GB RAM limit significantly impeded its performance, and even with SSDs, youâ€™ll notice performance issues when you hit that wall.
The new MacBook Air will most likely work as a solid secondary computer, but I would recommend staying away if you’re thinking of making it your primary: it simply isn’t powerful enough, unless all you do is check email and browse the Internet. In that case I would recommend the much more affordable iPad.