I was under the impression they were aiming it at more pc/console level power and not Tegra level power, IE real gaming and trip AAA titles they offer on steam. However I still can't see many people buying it. PC users of steam will already have a pc and obviously like pc gaming, if you wanted to game in the living room would you spend $300+ on a steam console with no content you can't play on the PC you already have, or $200-400 on the current or next gen consoles that do have exclusive content not available on the PC a gaming ecosystem, other cheap games(arcade and the like).
I really can't see who would buy the Tegra handheld stupid thing, nor the steam box. I have steam and ALL its content already, if I want go add to that I'll buy something that offers something MORE not something that repeats what I already have.
When you factor in steams pricing, it really just gets worse. I can see it getting even worse in as much as those developers who already have tie ins for MS/Sony who happily release the games on the PC on steam, won't it just discourage those guys from releasing on Steam if there is a competing console because then they can cut off most of steams content and make the steambox almost worthless?
If Valve created more than a handful of games themselves that would be one thing, but all the main games you want are Xbox/PS titles and they can just have those companies not go through steam in the future effectively locking them out of the consoles in the future and also hurting them on the PC?
It's also not very clear, it seems that there was a steam/valve "console" type device coming, but maybe these are more total PC type versions in a small form factor, IE trying to be Apple, make a desireable product and profit off the design prices rather than be Dell and profit off volume, and maybe there is a console version to be released at a later date. Or maybe the steambox everyone was expecting really isn't anything but a tiny PC and not really an attempt for Valve to get into the console type business at all. As above I can see a move to directly compete with MS/Sony as bad for them as dev's will chose consoles profits and then release their own "Uplay/origins" and cut Steam out of the loop, 5-10 years ago sorting out online distribution was new and more difficult, these days its a doddle, cutting Steam out would be easy and more profitable long term and make MS/Sony happy.
Steam sell a crapload of games, but most for small profits, indie games, and if their AAA titles dried up completely, then 90% of the users would leave and most of them wouldn't bother with most of the indie games either.