castElement.js

function castElement(el, target) {
    // Convert nodelists and weird dom stuff into arrays
    var attrs = [].slice.call(el.attributes, 0),
        children = [].slice.call(el.childNodes, 0);
        // create final element
        element = document.createElement(target);
    
    // copy attributes to new element
    attrs.forEach(function (attr) {
        element.setAttribute(attr.name, attr.value);
    });
    
    // copy children to new element
    children.forEach(function (child) {
        element.appendChild(child);
    });

    return element;
}