The Surface Hub 2 was unveiled as a 50.5-inch 4K display with a 3:2 aspect ratio, a webcam, and a touchscreen. The whole screen can rotate to be used in either orientation; multiple devices can be tiled together to build a giant screen that operates as one; and its software will support multiple user accounts.
In the second quarter of 2019, Microsoft will release the Surface Hub 2S. That offers the new display and form factor but running the current Surface Hub software-meaning no rotation, no tiling, and no multiuser. It's a sleeker, faster version of the current Surface Hub system.
In 2020, Microsoft is releasing the Surface Hub 2X. This is the version that will offer the original Surface Hub 2 vision, with all the extra software features. 2S hardware will be upgradable to 2X machines through replacing a removable processor cartridge housed in the back of the system. The cartridge is what will enable Microsoft's customers to make the switch to the Microsoft 365 powered Surface Hub 2X in 2020.