While it might be just a mistake on Samsung's side, since the actual product page is not available, the listed 860 Pro comes in a standard 2.5-inch form factor with SATA 6Gbps interface. It has a sequential read and write performance of 560MB/s and 530MB/s, which is slightly higher than the one on the 850 Pro. Unfortunately, the 4k random performance is not available at this time.
Currently, only the 4TB version is spotted and it comes with a rather hefty US $1,899.99 price tag or around $0.46 per GB. This is pretty much in line with the available 850 Pro, peaking at 2TB.
In any case, judging that the drive was leaked on Samsung's official site, we have every reason to expect an official announcement soon.