Valve may just be trying something new altogether here, such as when they created Steam in the first place. Seems like another venture for long-term payout.
This can change PC-gaming in the following ways:
1) High-end PC hardware can be subsidized and sold cheaply (even beating DIY's)
2) Valve makes up the money lost in subsidies on software sales ***
*) They are betting that their customers are not smart enough to just take the hardware and run... because I don't see how this can be locked down. Encrypted system and GPU BIOSes?
This isn't very different from what Sony did with the PS3 or Amazon was doing with its Kindle lineup.
1. I highly doubt that. Components alone will make this machine bleed red, and if you factor in logistics and manufacturing, it won't look pretty. Valve will have to rely on consumer loyalty because it will be hard to pry people away from PS4/Xbone when they are already so familiar with the operating environment and prices.
2. Keeping something running albeit being in the red? Sounds like the PSVita. That didn't turn out very well.
3. Let's hope not. Naive consumerism is what allows companies to get away with so much for so little.