This is what an open ecosystem does best.
The Jetpack, by British PC developer Piixl, is a computer that can attach to the back of a TV. If your TV stands on its own, the Jetpack clings to the television's unused wall mount point. If you were intending to mount your TV on the wall, the PC can reside between the two. These are the user needs that can only be addressed by allowing organizations (large companies, small businesses, hobbyist groups, and individuals) to explore in the niches either to "scratch their own itch"or differentiate their product.
The computer is branded mostly for SteamOS but can also be installed with a full version of Windows or Linux (which you can then install a Steam Client on). It is looking more and more like Valve is successful in herding OEMs.
The internals of this computer are quite interesting. It looks like they are attaching a 2-wide videocard 90-degrees to a mini-ITX motherboard with the other components spaced out around those two parts. Their official media claims that they will support any GPU (I assume they are not considering ones with extra- thick coolers) which should make future upgrades easy.
I may never purchase a Steam machine but I am excited that they exist. The purpose for the PC ecosystem is that every user with any need can find or create a solution. That is why general purpose computation devices exist: perform whatever information storage or manipulation the user desires. I do not have many of the needs that these boxes satisfy… but some people do and there should be systems available for them.
The Verge claims that the Jetpack will be available in January. I can sense a theme for CES 2014.