Obviously, no one actually has one of these yet. I took a careful look at the specs for it before I ordered mine. Here's why I think comments about what it lacks are perhaps off-base:
No Ethernet: I don't really feel like this is an issue. Virtually everyone who owns a Mac already has WiFi, and many places where you'd use an MBA have WiFi as well. I think the only time I ever actually used the Ethernet port on my MBP was when I was doing a gigantic (50 GB) file transfer, and using the wired connection was faster than using wireless. Otherwise, I've always only used wireless.
No built-in optical drive: Again, I don't really feel like this is an issue. I've used my MBP's SuperDrive to install a few apps (Office 2004, Photoshop Elements), but I've never burned a CD or DVD in my MBP, and I don't install apps on the road. The Remote Disc functionality should suffice for most people, and for everyone else there is the $99 external SuperDrive option which allows you to "leave the drive at home" if you're not going to need it with you.
Not enough disk space: I think people are getting a bit spoiled when it comes to disk space. We see computers being fitted with TB hard drives now, and we wonder if 64 GB or 80 GB will be "enough". For most people, using this computer as it's meant to be used, the answer is yes, it's enough. Given the small screen and slower CPU (compared to larger notebooks or desktop machines), you shouldn't be using this for video editing, anyway... and remote disk options, where you might store your files on an Internet-accessible location (like Windows Home Server; why doesn't Apple have something like that?), suddenly make it possible for you to access all kinds of files, even if they're not actually in your notebook.
Not enough CPU power: Again, this is not meant to be a video editing or gaming machine. The 1.6 and 1.8 GHz CPUs are almost as fast as what is currently offered in the Mac mini, and I don't see people complaining that minis are underpowered.
Not enough FireWire/USB ports: How many USB ports do you need? One should suffice for syncing your iPhone or iPod. And I doubt that people are going to be lugging around multiple USB devices and plugging them into the MBA simultaneously while they are away from their desk. As for FireWire, the only things that really use it are powered external hard drives, which you can't use while away from your desk, and video cameras.
No removable battery: When you get the form factor down this small, with virtually no wasted space within the volume of the chassis, things like the hardware necessary to allow a battery to be removable take up valuable space. Imagine how much larger an iPhone or an iPod would be if they had removable batteries. Imagine how much smaller other companies' phones and laptops could be if they started making batteries permanently installed. It's a trade-off; removable battery, or smaller chassis. (My only hope here is that Apple's battery replacement process is FAST: Ideally, they should be able to do this in the Apple Store, without you having to ship your MBA anywhere. The $129 price is comparable to the price of a MBP battery, and factors in installation costs. Apple may actually be losing money on this, given the high cost of skilled technical labor.)
Remember, folks: This is a notebook. You are sacrificing features (ports, storage space, etc.) in order to get portability. The more portable it is, the more features you have to give up in comparison to a less portable solution, such as a Mac Pro. The trick is, as Jobs said, to give up as little as possible, and to give up those things that you truly don't need. If you compare the volume and weight of the MBA to other notebooks, or even other desktops, I think you'll find that it is perhaps the most powerful machine available anywhere on a power:volume/weight basis.
I think Apple did a pretty good job. I would like to see the MBA2 come with a slablike (MBP, MB) configuration, rather than a wedge... but the MBA's wedge is pretty nice. And the MBA2 should also include WiMax or 3G support, so that we can be wireless anywhere.
No Ethernet: I don't really feel like this is an issue. Virtually everyone who owns a Mac already has WiFi, and many places where you'd use an MBA have WiFi as well. I think the only time I ever actually used the Ethernet port on my MBP was when I was doing a gigantic (50 GB) file transfer, and using the wired connection was faster than using wireless. Otherwise, I've always only used wireless.
No built-in optical drive: Again, I don't really feel like this is an issue. I've used my MBP's SuperDrive to install a few apps (Office 2004, Photoshop Elements), but I've never burned a CD or DVD in my MBP, and I don't install apps on the road. The Remote Disc functionality should suffice for most people, and for everyone else there is the $99 external SuperDrive option which allows you to "leave the drive at home" if you're not going to need it with you.
Not enough disk space: I think people are getting a bit spoiled when it comes to disk space. We see computers being fitted with TB hard drives now, and we wonder if 64 GB or 80 GB will be "enough". For most people, using this computer as it's meant to be used, the answer is yes, it's enough. Given the small screen and slower CPU (compared to larger notebooks or desktop machines), you shouldn't be using this for video editing, anyway... and remote disk options, where you might store your files on an Internet-accessible location (like Windows Home Server; why doesn't Apple have something like that?), suddenly make it possible for you to access all kinds of files, even if they're not actually in your notebook.
Not enough CPU power: Again, this is not meant to be a video editing or gaming machine. The 1.6 and 1.8 GHz CPUs are almost as fast as what is currently offered in the Mac mini, and I don't see people complaining that minis are underpowered.
Not enough FireWire/USB ports: How many USB ports do you need? One should suffice for syncing your iPhone or iPod. And I doubt that people are going to be lugging around multiple USB devices and plugging them into the MBA simultaneously while they are away from their desk. As for FireWire, the only things that really use it are powered external hard drives, which you can't use while away from your desk, and video cameras.
No removable battery: When you get the form factor down this small, with virtually no wasted space within the volume of the chassis, things like the hardware necessary to allow a battery to be removable take up valuable space. Imagine how much larger an iPhone or an iPod would be if they had removable batteries. Imagine how much smaller other companies' phones and laptops could be if they started making batteries permanently installed. It's a trade-off; removable battery, or smaller chassis. (My only hope here is that Apple's battery replacement process is FAST: Ideally, they should be able to do this in the Apple Store, without you having to ship your MBA anywhere. The $129 price is comparable to the price of a MBP battery, and factors in installation costs. Apple may actually be losing money on this, given the high cost of skilled technical labor.)
Remember, folks: This is a notebook. You are sacrificing features (ports, storage space, etc.) in order to get portability. The more portable it is, the more features you have to give up in comparison to a less portable solution, such as a Mac Pro. The trick is, as Jobs said, to give up as little as possible, and to give up those things that you truly don't need. If you compare the volume and weight of the MBA to other notebooks, or even other desktops, I think you'll find that it is perhaps the most powerful machine available anywhere on a power:volume/weight basis.
I think Apple did a pretty good job. I would like to see the MBA2 come with a slablike (MBP, MB) configuration, rather than a wedge... but the MBA's wedge is pretty nice. And the MBA2 should also include WiMax or 3G support, so that we can be wireless anywhere.