It is working. I sure didn't expect platform parity when they announced it, and yet, I don't feel like a 2nd class citizen anymore. Linux games are now cross platform, not terrible ports. And the 3 largest game engines now compile to linux out of the box (more or less). The support burden has lessened as well. It is great all around.
Oh, I didn't mean to imply that it didn't work, or there were shortcomings in the platform... only that sales haven't been great (think Steambox, etc).