With all of the talk surrounding the MacBook Air (much of it being "Apple, WTF?!?!"), I thought I'd share why I have one on order.

I work at a Mac software company; over the years, my job has morphed from doing development to designing products, managing their development, and in general running the company. As such I have 3 computers I use on an almost daily basis: work desktop Mac, home desktop Mac, and a laptop. I find that what I tend to do more than anything else these days is talking to people; via email, AIM, Skype, and over the phone.
Any real intensive work, I do on either desktop... but I end up using my laptop more than any other machine. I find that the bulk of what I do on my laptop is answering emails, browsing the web, and sometimes product testing. I also travel relatively frequently to various meetings, trade shows, and events, at which I keep in touch with the office via my laptop.
I've used a MacBook Pro for this, and it has served me well. However, it can weigh heavily on your shoulders lugging it through airports all day... and don't even think about trying to open it and do any work on a flight in coach. Not happening.
So I'm open to the idea of a smaller, lighter, but still full featured laptop that can be my "third machine." Clearly I'm a bit of an exception; I'm in the industry, so it makes sense for me to have multiple machines to work on. It's what I do for a living.
However, I don't think I'm alone in the desire for a lightweight "sidekick" machine. I will let you know how the MacBook Air works out in this regard.
Regrets? I have a few. The way Apple has outfitted the MacBook Air, it is essentially a lower-weight, thinner, feature-trimmed version of the MacBook Pro. That's fine for what it is, but there are two major things Apple could have done to make this machine more than just a MacBook Pro "lite", and turned it into something else entirely.
Better battery life. If this is truly meant to be a wireless, cordless, untethered laptop, give it battery life that sets it apart from the pack. Allow me leverage its waif-like nature to use it on the go for extended periods of time. Make the freedom offered by its thin profile and light weight be matched by the lack of a need to constantly be suckling a power outlet. Certainly I realize the dichotomy of wanting more battery life in a lightweight package, and yet I remain hopeful.
Give me EVDO (3G). A truly liberating laptop would offer me cellular wireless connectivity, so that I can use it anywhere on the go. If this is truly an "Air", then it should offer wireless Internet via EVDO (3G), if only as a BTO option (and they could offer GSM in other countries, again as a BTO option). A number of existing laptops offer this capability, and it would fit in with Apple's "Air" wireless concept perfectly.
That's it; a modest list of desires. Other things that people seem to have their panties in a bunch about really don't bother me. The DVD player on my MacBook Pro hasn't worked ever since the TSA repacked my bags like a rabid orangutan one trip, so I won't miss it.
I can't remember the last time I plugged a firewire device into my MacBook Pro, so the loss of that port (and others) means little to me, given what I use the laptop for. I also surprisingly don't really care about the lack of an Ethernet port; on trips I bring an Airport Express with me for Ethernet hookups, which allows me to use my laptop... well, like a laptop!
Even the lack of a user-changeable battery isn't that big of a deal to me. I never bring spare batteries with me. The downside here will only come into play when the battery no longer holds its charge well. Assuming Apple does a decent job of replacing it quickly -- and securely -- I think it will largely be a non-issue, at least for me.
Really, it's just about perfect for a sidekick/road warrior machine for me. Just give me more battery life, and don't make me hang a USB dongle off of the machine to use the Internet via EVDO, and it'll be downright perfect for me.
Your mileage, of course, may vary. But this is clearly a niche laptop, an expansion of the line rather than a replacement for anything that exists already. It's important to see it in that light.
However, I don't expect this machine to be a massive hit for Apple. It's too niche for that... and if the product does end up flopping with consumers, there's at least one thing you can count on: it'll be featured in an awful lot of movies and TV shows.

