Valve Attending Gamescom

The listing states that they will be attending Hall 4.1, Stand: A031. They will be showing something to do with PC and controllers.

It's no secret that Valve has been hard at work designing a controller for it's Steam Machine. Perhaps they are going to reveal that the Steam Controller is being made PC-compatible. Or perhaps they will just be showing off the controller ahead of next years release.

Another school of thought is that they could be showing the controller as a smokescreen - and going to announce Half-Life 3.

Unlikely, but still we can hope.