"A job listing on Valve’s site confirms that the company will begin developing hardware. A listing for an industrial designer says “Valve is traditionally a software company. Open platforms like the PC and Mac are important to us, as they enable us and our partners to have a robust and direct relationship with customers. We’re frustrated by the lack of innovation in the computer hardware space though, so we’re jumping in.”
It sounds more like they are looking into developing peripherals than an actual new gaming platform, but it sure is interesting. The IGN article links back to the actual job listing, so that's pretty solid. Of course, there is no mention of what exactly they will be developing, which is where the speculation comes in. Any ideas? More rumors, speculation or hints?