I forgot to mention in the 1.0.2 release notes, the other day, that there was a minor API change. This was a mistake, as we should’ve held off on making an API change until the next major release (jQuery 1.1).

As summarized by Steven Wittens, here is the premise behind the change:

In jQuery 1.0.2, the first argument to the ’success’ callback has been changed to return the actual data rather than the XMLHttpRequest object. Use the ‘dataType’ argument to $.ajax() to control how the data is returned. Note that jQuery can now parse XML, JSON and JavaScript for you this way.

jQuery 1.0.1

$.ajax( {
  success: function (xmlhttp) {
    var data = $.httpData( xmlhttp );
    // 'data' holds the response data from the server
  }
);

jQuery 1.0.2

$.ajax( {
  success: function (data) {
    // 'data' holds the response data from the server
  }
);

Thanks, Steven, for the synopsis – and sorry, everyone, for the inconvenience!