I heard about this on TWIT, and had to see it for myself. The Optimus is a keyboard that uses OLED technology to remap the keys depending on what application you're using. (In the examples below, from typing to Photoshop to Quake) There is an additional group of app-switching keys, seen above.
Already long overdue, the Optimus is now promised for February. If this thing ever really comes out at even a semi-reasonable price -- and it's fully customizable -- it will be very tempting.