Well it was Valves plan not to have one 'Steambox', but to have a sort of 'OS/service' that other companies can utilize, kind of like what Android is doing in the mobile space.
But who is this market for? Enter the Amazon, and well...
Steam should help bring Linux Gaming to light first, then we can go for loyalty-free gaming, and all those who don't have a Microsoft OS can become Steam client$. That could be their steam box train.
We asked ourselves the same question for the WiiU, who is that market for? Hardcore Nintendo fans sure, they bought the system as it was the next step in their history.
In terms of another physical box for Steam, what advantages does it carry? I'm sure it will have another OS, as Gabe is adamant to bring Steam to new platforms. But why would I game here over my rig?
Affordable gaming could come down to Amazon vs Steambox, but Steam isn't as recognized by the masses, and it could not have all the media apps the Amazon system is bound to have.
They're both digital distribution giants, but will Steam foray into the world of entertainment beyond gaming? This could be the deal-breaker, that, and the household name.
Does the Amazon box have hats? I bet Steambox has hats. People like hats.
I can't see Amazon entering the market with an offering to rival the big 3 but i doubt they would enter the market with a low-powered OUYA type device either. It's got to be an On-Live streaming style service using their EC2 farms and the infamous infinite power of clouds. Well that would be my guess.
If you really want to be blunt about it, it could really come down to ''what does this console have over the other console?'', in which case the Steambox would be looking at taking in extra ventures to deal with the abundance of media that is reaching online stores today. Steam would have to expand its business to survive, much like PS3, 360, Wii when they integrated netflix, and other apps.
Everyone wants a piece of the cake, it all comes down to who slices it better. (The bigger, the better)