Best Buy has put up a preorder link for the flagship "wallpaper" W7 at $8K. Whether that turns out to be true is anyone's guess, but I suspect that means similar, possibly lower prices, for the rest of the line as the 2016 models at launch. There are also preliminary, untested reports that input lag in both SDR and HDR modes has dropped to 21ms, which is a third less than the 2016 models after the firmware added HDR Game Mode. It also adds support for two new flavors of HDR: HLG (developed by the BBC) and Advanced HDR (by Technicolor), neither of which has any content for it yet.
Initial claims are that the set is 25% brighter (1000 nits?), has almost all of the DCI-P3 color space represented, and "supports" Dolby Atmos. And curved screens and 3D have been dropped for all models.
Now whether any of this is worth the dough over a close out deal on a 2016 model is a personal choice. But while I wouldn't necessarily agree that there are no "meaningful image quality improvements", the 2017s are definitely an incremental upgrade. Plus, there's no telling until the reviews come out on whether there have been significant improvements in shadow detail, uniformity, and motion that are still not ideal in the 2016 models (but a huge improvement over the 2015s apparently).
[EDIT: Or what Ginger and Gordon said. :)]
As for Sony, the sound is actually coming from screen vibrations. There are no standalone speakers on the set. I've read mediocre to moderately positive stuff about it so far. I'm looking forward to hearing about the motion processing (and the price) compared to LG. Surprisingly, they announced Dolby Vision support, but no HLG or Advanced HDR. And the sandwich board stand looks like a disaster to me, especially since I don't wall mount.