Pictures speak for themselves. Though some might argue about its authenticity, the guys at TechPowerUP! will vouch for you that yes, this may be the single GPU flagship of NVIDIA's upcoming GeForce 700 series. And it's not just about the insignia these cards hold but the subtle differences TPU! staffs have discovered between it and the GTX Titan. These are: near the PCI-Express interface- location of PCB number, arrangement of termination resistors etc.
So behold the GeForce GTX 780 : (don't get too excited though. You know, who knows ?)
And always a great source of info lies in the forums. So the SOURCE.