Third-generation V-NAND memory will feature up to 48 layers, allowing Samsung to make NAND flash memory chips with a capacity of 256Gb, twice as much as the 128Gb it achieves on the current, second-generation 32-layer V-NAND design. This effectively enables Samsung to double the storage capacity of its SSDs.
The first products announced were the 4TB versions of the SSD 850 PRO and the SSD 850 EVO. These will retain the standard 2.5in 7mm form factor and operate using the SATA 6Gbps interface. They are due for release in early 2016, which will be less than twelve months after the release of the 2TB editions.Source: Bit Tech
Next up is the SSD 850 EVO M.2 1TB. Previously, this was limited to just 500GB. As with the 4TB SSDs, this drive is also scheduled for release in early 2016.