So, yeah: Adobe’s using Flash-derived technology to make HTML5 more competitive with Flash.
Crazy, right? Not at all: this increases your ability to present visually rich experiences, and that increases Adobe’s ability to sell you tools for creating those experiences. The different playback technologies are just means to those ends.
Working with Opera, they’ve put together a spec and submitting it to the W3C. Latest nightly of WebKit has it implemented. Really good to see Adobe looking forward like this.