I also noticed auto_play=false was not working properly. As a work around you can call the pauseVideo() method after loading.
$(function () {
window.onPlayerLoad = function () {
var player = $("#twitch_embed_player")[0];
player.pauseVideo();
};
swfobject.embedSWF("//www-cdn.jtvnw.net/swflibs/TwitchPlayer.swf", "twitch_embed_player", "640", "400", "11", null, {
"initCallback": "onPlayerLoad",
"embed": 1,
"auto_play": "false",
"channel": "lirik",
}, {
"allowScriptAccess": "always",
"allowFullScreen": "true"
});
});
and an example.