Between this and Valve's push for gaming on Linux, another of Linux' Achilles heels is solved. What else is missing before the Linux desktop is adequate for pretty much everyone?
Much like web apps, YouTube, Netflix etc. today already work flawlessly on Linux, so will gaming too with this development. For most people, the browser is already the only "native" desktop application they use on their computers.
Web apps and web video finally made the Linux desktop viable, but also irrelevant in the bigger picture.