Supports MP3 format

Test source

    var audio = this.audio;
    finish(/probably|maybe/.test(audio.canPlayType('audio/mpeg; codecs="mp3"')));

Browser issues

Compatibility results are NOT shown in real-time

BrowserStatus

Copyright © 2011, SoundCloud Ltd., Tomás Senart, Yves Van Goethem

"Are We Playing Yet?" is distributed under the terms of the BSD License