madrobby/zepto — pull request #367 by buger (2012-01-08 16:43:27+00:00)
Title: Added supports for dataType:'jsonp' to $.ajax

You don't have to specify "callback=?" parameter.
Now this should work:

$.ajax({
url: "http://some_url/api.jsonp",
dataType: "jsonp"
});

This is helps when migrating from jQuery.