I don't see that happening, partially because it would be very un-Valve-like, and partially because it would be stupid.
Valve, in the past, has pushed for more hardware to be able to play its games, not less. Sure, it started out on Windows, but it's made a very respectable delivery platform for the Mac, and now they're on their way to Linux. Saying, "the only way to play our game is on this one specific piece of hardware you have to buy from us" would go against quite a bit of what they've been doing over the past 5 years.
Also, it would be stupid. The people who are drooling over the possibility of HL3 are PC gamers. People who invest cash in gaming rigs, who probably like building their own computers. Saying, "Want HL3? Now you have to buy our hardware!" would be more or less giving their fans the middle finger.
I expect the Steam Box will be hardware, and possibly a customized Linux distribution. And I expect that if you want to "build your own" Steam Box, you'll be able to.
Valve, in the past, has pushed for more hardware to be able to play its games, not less. Sure, it started out on Windows, but it's made a very respectable delivery platform for the Mac, and now they're on their way to Linux. Saying, "the only way to play our game is on this one specific piece of hardware you have to buy from us" would go against quite a bit of what they've been doing over the past 5 years.
Also, it would be stupid. The people who are drooling over the possibility of HL3 are PC gamers. People who invest cash in gaming rigs, who probably like building their own computers. Saying, "Want HL3? Now you have to buy our hardware!" would be more or less giving their fans the middle finger.
I expect the Steam Box will be hardware, and possibly a customized Linux distribution. And I expect that if you want to "build your own" Steam Box, you'll be able to.