Don't count on it. The X80 will likely beat the 980Ti. Expect X70 to only beat the 980.
You can think what you like, but that doesn't mean it is more likely, it's far more likely for the story to repeat itself based on previous generations, unless you can justify it with some data.
According the first reviews of the following cards here:
A GTX 970 was roughly on par with GTX 780 Ti, it was simply a more efficient chip, doesn't matter it loses in some of the specs like transistor count and CUDA cores, and the preliminary specs of GP104 show again an increase in RAM compared to GTX 980 Ti, with roughly the same amount of transistors, even if the X70 ends up with 2048 CUDA cores based on 980 vs 970, it should be enough based on GTX 970 vs GTX 780 Ti numbers, just in case this wasn't enough maybe because architecture limits, base clocks are expected to increase significantly based on GP100 chip.
This doesn't matter for GTX 980 Ti owners because if story repeats itself, X80 will not be significantly more powerful than a GTX 980 Ti (specially the heavily OCed) or X70, so the price increase over X70 will not be justified (15% higher performance at %50 higher price), although Nvidia might want to cripple X70 a bit more this time to avoid that.
Actually it might not matter to most already with a GTX 970 or better, because the increase will probably not be big enough to make a jump into 4K 60fps in new games for example, you can easily wait another year for the full fledged Pascal.
