It seems as though if you're interested in picking up a Steam Machine for your living room, you will only have third party options to choose from.

In speaking with various media outlets, Gabe Newell said that Valve has no current plans to release a first-party Steam Machine to the public.
“We’re going to continue to make that decision [about releasing our own Steam Machine] as we go along,” Newell said. “We have plans to build more machines, but we also expect that users will be really happy with the range of offerings from these hardware manufacturers.”

“I mean, we’ve made 300 [of them], which is very tiny stuff. You know, we’ll make what we need to. We really view our role in this as enabling. So we’ll do whatever is going to be helpful to other hardware manufacturers – whether that’s with controller design or something specifically tied to boxes. It’s very much about how we can collaborate with the chip-makers and the system integrators. What’s the most useful thing for us to do? Part of the reason for holding events like this is to get feedback from them about what are the next problems they’d like us to take on.”

Steam Machine/SteamOS designer, Kassidy Gerber, expanded a bit on what Gabe said earlier.
“Right now we’re not planning to bring the prototype to market. It doesn’t mean we never will, but right now we’re really working with third-party hardware to build their own Steam Machines. We think they know their customers and they know hardware better than us right now.”

“In the first year of Steam Machines, our main audience is people telling us they want to bring their Steam library into the living room. Right now, there’s no way for people to really do that well.”

With the cheapest of the third party offerings starting at roughly $500 (USD), do you really think the Steam Machine is going to gain momentum with mainstream audiences?