the card released as the GTX680 originally was slated to be the GTX660(hence the GK104 gpu in it). Nvidia decided to cash in when they saw thier "mid-range" card was going to be faster than AMD's newest flagship card, so they revised the card to be the GTX680. GK110, which is schedualed for release in August, is what was planned to be the GTX680.
“Never underestimate the predictability of stupidity.”
“Amd....definitely a blond female.....not much on the cpu side, but always strutting about showing off her gpus......wow that was bad. I apologize.” -ensabrenoir