Q: How do you remove the back?
There are three screws, and they're captured so they don't come out at all, so you don't need to worry 'Oh my God, where did that screw go?' Loosen the screws, and the back will simply come off, downward first, and the back is off -- you now have full access to the machine. AirPort is easy to add. The antenna are embedded in the computer, so all you have to do is get your AirPort card, plug it in, push the antenna jack in, and you're off and running. You can put up to 2GB of RAM inside, with standard 400MHz DDR memory.
Q: What about the rest of the machine's insides?
The power supply isn't a brick left out on the floor, it's all integrated inside. It's really amazing, because this is the most compact design we've ever done for an iMac, yet it's the most accessible. It's very easy to service this, which is why you see tabs, because it's easy enough for a service person or even a customer to self-service on this product. There are even four indicator lights on the motherboard that an Apple Care person will tell you to look at the lights, and depending on what's lit up, can tell you the state of different sub-systems.
Q: Anything special about the ports?
You have standard analog audio out, but it's also one of the combo jacks like we have on the AirPort Express that allows you to do digital out as well, so you can do 5.1 surround sound, for example, from DVD Player.
The best article on the new iMac so far. I like the power brick being internal -- the main cord is a standard plug.
The strangest omissions are no GB ethernet (would have cost very little) and having to build-to-order for Bluetooth and pay $50 extra. Bluetooth is integral to its elegant design and minimal cords. This is so odd I have to figure it was a desperate attempt to hit a price point. Bluetooth added after purchase is external only!
The 400 MB/sec rather than 800 MB/sec firewire may be related to technical issues. It does include USB 2.0. This doesn't give one a warm feeling about the future of firewire.
It's easy to add an Airport card, so that needn't be an initial purchase.