[spicyj]

The suggested way of doing this is define a new component like so:

  var BigButton = React.createClass({
    render: function() {
      return (
        <Button
          {...this.props}
          className={'btn-large ' + this.props.className} />
      );
    }
  });

(Before React 0.12 introduced the JSX spread syntax, this was handled by transferPropsTo.)