GTX 780: How will it perform compared to the Titan and the 580?

Hey guys,

Any idea about how the upcoming 780 (to be released in just four days, now!) will compare to the older 580 and its GK110 counterpart, the Titan? Will it be much better than the 580, or will it be a flop for Cycles like the 680 was? Am I right in assuming that anything based on the same chip as the Titan has got to be at least pretty awesome, if not really awesome, or is Nvidia artificially limiting it? Anybody know?