The best hack I've seen since Brad Neuberg did AMASS in 2005: Arek Korbik implements Vorbis in Flash, with no dedicated Vorbis support provided by Adobe as part of Flash. It's a god-level piece of hacking.
What Arek's hack means is that new sound formats can now be implemented in pure AJAX and deployed with browser-borne technology. This breaks the logjam at MP3, where new audio formats could never reach wide deployment because the only one that Microsoft, Apple, and Adobe could agree on was MP3. The result of the logjam was that innovation related to audio file formats was over in about 1998.
That innovation can now start up again. We can expect growth of patent-free codecs like Vorbis and FLAC. I'll bet there will be a JSON-based audio format based on Vorbis. And in the long term, freaky Big Daddy Roth audio files with chromed metadata, embedded blenders, etc.
Upate: I'm getting a little pushback from people who feel that (1) there's nothing new here because it has been possible to do Vorbis using Java applets for a while and (2) this method doesn't support video.
Java is not a viable option. Most people don't have Java installed, and the people who do have it installed won't tolerate the slow and ugly startup. About the need for video, let's not get ahead of ourselves. One thing at a time.