Even though the iPad is another month away, accessories are available right now.
At Maccentric I picked up a Cygnet "Lavish" case for my new toy:
It's a beautiful soft padded leather case with a soft interior and a magnetic clasp. The iPad slides in sideways from the left so there's no way it can slip out when closed. There are openings for the dock connector and speaker at the bottom and the headphone and power button at the top.
Unfortunately there is no opening for the volume and the screen rotation lock switch. (You can push the volume control through the leather without too much trouble).
The wide margin around the screen means that the iPad is securely held. As you can see above there's a hole to access the "home" button.
The opening for the screen is a tiny bit too narrow and can block the view of pixels at the edge. It's a little bit hard to extract the iPad but I think with wear this will improve.
Overall it's a lovely case and makes reading a book on the iPad as much of a tactile pleasure as a well bound book. $69.