Unless Amazon's listing is incorrect, we'll be seeing Rise of the Tomb Raider on Xbox 360/One, PS3/4 and PC.
From the announcement:
Steam in-home streaming will allow you to play a game on one computer when the game process is actually running on another computer elsewhere in your home. Through Steam, game audio and video is captured on the remote computer and sent to the player's computer. The game input (keyboard, mouse or gamepad) is sent from the player's computer to the game process on the remote computer.
This means you'll be able to play a game that's running on your gaming pc on your terrible old laptop, so every time you get killed in a multiplayer game, you'll have to wonder if that dude just sniped you from his toilet.