FYI I did a JavaScript API library for dealing with Sharepoint: http://aymkdn.github.io/SharepointPlus/
One of the good thing is that you don't need to worry anymore about the CAML Query. For example in your case you could do :
// define your date in JavaScript
// and use $SP().toSPDate() to convert it to the right format
var eventDate = $SP().toSPDate(new Date("2013/12/10"));
// call $SP().list().get() to get your data with the "where" parameter
$SP().list("Name of your list").get({
fields:"EventDate",
where:"EventDate >= '"+eventDate+"'",
orderby:"EventDate DESC"
}, function(data) {
for (var i=data.length; i--;) console.log(data[i].getAttribute("EventDate"))
})
Note: you can check the browser console to check if there is any error