An official GTX 680 video from Nvidia has been released that explains several features such as GPU Boost, improved PhysX, and TXAA.
Even though there has been a bit of controversy over whether or not this card is the real GTX 680 due to TDP, die size, and the card’s length, this new GPU does pack a lot of new features.
Source: Overclock.net
Right now it comes down to price. There were some leaked benchmarks that claims the card just inches out above a 7970, which is still decent, but if it isn’t priced well Nvidia could have a hard time declaring a clear victory over their competitor.