There is a model with black keys and brushed aluminum surround, so it could, kind of, match your iMac. Although the new keyboard that comes with the new iMacs could probably do a better job.
Anyways, this keyboard has a lot of ergonomic stuff in it, including curved keys so they fit to your fingers better, that’s not all that new though. It also has the scissor-foot key spring system to make it more comfortable and make the keyboard last longer.
Its mostly a run of the mill keyboard, but it appears they shrunk this keyboard a little compared to some as they removed a lot of the space that is usually between the end of the right Enter key and the start of the number pad, which could make things a little different. It does have some hotkeys and favorites buttons at the top, but mostly it just looks good. Its wired though, with a USB connector, and it will cost you an unknown amount and you can buy it at an unknown time.
Thermaltake Soprano Aluminum Keyboard [via Fareastgizmos]