Nice find, although with the recent disdain towards the Oculus Rift, I hope the developers of this framework are working on getting the HTC Vive supported soon.
What disdain for the Oculus Rift?
Shipping delays and putting it on Best Buy shelves before sending it to pre-orders made many upset.
Meh, Vive had the same problems. I know people who were disappointed (myself included) but disdain is a strong word.
But then we live in a world where game developers get death threats over delays, so I don't doubt there are strange angry people out there who'd hold a vendetta.
A-Frame builds on the WebVR API and Polyfill, it's not meant to be built for specific devices. They've built the framework to support any new upcoming devices. Since this is all open-source and community driven, it will take time especially when these devices are still in relative obscurity and cost quite a bit. HTC hasn't done any work on contributing how the devices should support these existing APIs (that are still quite in flux), which would be an awesome contribution to the community.