I had an idea, more a need, for something like this many years ago. It came back to my mind when OpenBSD needed funding partly due to all the different pieces of hardware they test on. Wouldn't it be nice for portability-focused projects to be able to pool together resources on hardware to cut down on it?

Anyway, awesome to see AWS doing it in practice. As usual, it will be more interesting to see what happens when competition turns up. Cloud space has more innovation and cut-throat competition than many IT sectors. Can't wait to see what the competition costs. ;)