Tom's Hardware found evidence that Samsung's next-gen NVMe SSDs are already circulating in the wild. These models are expected to be released in January 2018. They use 64-layer TLC V-NAND memory from Samsung and are expected to be introduced as the 970 and 980 SSDs.
Pictured below you can see the OEM version of the 980 SSD, which sports impressive performance:
The performance, according to the seller's listing, looks very good. The 1TB model delivers up to 3,200 MB/s sequential read and 2,400 MB/s sequential write performance. Random 4KB numbers run up to 380,000 IOPS read and 440,000 IOPS write. We've already seen a CrystalDiskMark result with even higher performance but have yet to verify the legitimacy of the image.