Earlier quoted context omitted.
That is interesting news, but turn the OS market upside down? You can't be serious.
yes it will - Steam is a juggernaut which will trigger purchase/usage decisions. Creators of libraries and frameworks will have to comply with the standards that Valve will come up with (and come up they will). For example what audio framework will your distro use - Jack? OSS? Pulseaudio? They will have to use what Valve wants you to use, if you want to play their games. Multimonitor support ? HDMI? use the toolkits…
Now make it 1/10th of 1/10th!
Unless they convince a significant number of other publishers to do linux versions (while they won't even do mac versions) it's not going to be very exciting.