We came very close to using WebGL for a Seattle Times special report that will come out next week. Now that iOS 8 has shipped with support for WebGL, albeit in an unstable and slightly buggy form, it's common enough that I felt comfortable using it (with a scaled-down 2D fallback) for our audience. In the end, we went with a different design language and shelved the WebGL experiments, but the experience has left me very excited about the potential for mainstream usage.
There's an obvious parallel here, which is the first two major versions of Android. Because it was designed to run on low-end hardware, Android drew all its UI via software until 3.0 (and hardware acceleration didn't become widespread until 4.0). The resulting lag was never as bad as critics claimed, but it did mean that a lot of Android looked and felt a bit utilitarian. You wouldn't see something like Material Design emerge until the system supported using the GPU for rendering ordinary UI.
It's not a coincidence that Google's moving to Material Design on both Android and the web. Its design language — a smoothly-animated world of flat, geometric shapes — is attractive, but more importantly it's well-matched to the kinds of flat, geometric shapes that can be animated fluidly in a browser, using the 3D acceleration that's already built into the composition layer. Web Components will give developers a way to package those elements up, and make them reusable. Flexbox makes their layouts scalable and responsive.
But for the web platform to move forward, we need more than just a decent look and feel. We need the ability to write the kinds of applications that people insist that it can't run. WebGL is a step in that direction: graphics with near-native speed and capability, instantly deployed and paired with a surprisingly powerful UI toolkit. The kinds of apps and experiences we can write othe web, for a mainstream and mobile audience, just got a lot bigger. And I for one am looking forward to pushing those boundaries as much as I can.