NVIDIA may not have said anything officially, but its many partners have sheared a good chunk off the price of the company's most powerful single-GPU PC graphics adapter.
Indeed, the GeForce GTX 680 will be selling for under $400 / 400 Euro from now on.
Given the existence of cards sold for over $450 / 450 Euro, and even some $500 / 500+ Euro models (albeit with double the memory, 2 GB instead of 4 GB), this is quite a large step.
Obviously, it is a preventive measure, of sorts. Advanced Micro Devices will soon start selling Radeon HD 8000 adapters, so NVIDIA is offering prospective buyers a reason to purchase its own boards before that.
Needless to say, it is also a method meant to exhaust the inventories of GTX 680 before GTX 780 gets launched, a few months from now.