EVGA GeForce GTX 680 MAC 4GB 256-Bit GDDR5 PCI Express 2.0 Video Card Support Apple system and Win dual system... Apple system driver free - Newegg.com
EVGA First to Launch 4GB GeForce GTX 680, Also Intros Several Overclocked models including Hydro Copper Series GTX 680
Nvidia GeForce GTX 680 specs and images leak - The Verge