Don't expect any improvements over 1080Ti in the newly released cards. As others have noted, these most likely, will be a refresh. Therefore below could be expected:
- If it's a refresh based on 1080Ti shader count, there might be 10% increase (saturation of TDP, even with process optimizations / die shrink)
- If it's a refresh based on the 1070Ti shader count, there might be 15% increase (more room).
- If it's a new card based on cut down version of Titan V, see case of 1080Ti again. As the Titan V is about 25-35% faster than 1080Ti depending on the applicaiton, it is unreasonable to expect same gain for non Titan series.
All in all, my recommendation (given market conditions) is to load up on the Titan Xp (collector's edition cards) as these are retailing now below 1080Ti pricing and will definitely have better resell value. At the same time, with optimized temperatures these cards hash at least 10% faster than aftermarket 1080Ti's.
Why do you say that if based on 1070Ti shader count, we would see a bigger improvement of 15%? Genuinely curious about this from a more technical standpoint.