If they price the 980ti between the 980 and the titan x and it outperforms the titan then there's going to be a few irate customers in the nvidia camp!
This is what happened the last time with the first Titan so why wouldn't they do it again?
There is TDP headroom in the Titan X to allow for better clockspeeds on the 980 Ti, but probably not an awful lot. The real issue is likely to be that Titan X is the full GM200 chip (the first Titan wasn't, it had one missing SMX while the 780 Ti was the full chip) so if Nvidia makes the 980 Ti as the full GM200 chip with higher clockspeeds, then they obsolete the Titan X completely. At least the last Titan had the full FP64 switch but these Maxwells basically have no compute in them at all, they're just full blown gaming GPUs. This is another reason why the Titan X has 12GB of VRAM - pure marketing to set it apart from the upcoming 980 Ti.
So for me it's likely that the 980 Ti will be missing one SMX but have higher clock speeds, making them perform
very closely but with half the VRAM being what stops the Titan X buyers from being too irate (even though it's useless for gaming purposes).
One thing I know for sure is that the 980 is gonna be a lot cheaper this time next month.