According to this supposed GameStop daily newsletter, the DS Lite Onyx handheld has been discontinued. The newsletter reads:
DS Lite Onyx hardware systems have been discontinued and stores will no longer be replenished on this product. Once your store sells through its current stock of this item, please remove any empty DS Onyx display boxes (onyx color only) from the sales floor and discard. Please continue to display the other colors of the DS Lite system display boxes on the sales floor (eye level and above perimeter of DS software section, above the DS accessory section, etc).
This isn't unusual. The White DS Lite was apparently discontinued and replaced by the Silver DS Lite. If this is true, could it mean the Onyx DS Lite has been discontinued to make way for the black DSi?