• Fix: getAttribute now returns null for attributes that are not present, as per DOM4 (but in contradiction to DOM1 through DOM3).
• Fix: static NodeList-returning methods (such as querySelectorAll) now return a real NodeList instance.
• Change: NodeLists no longer expose nonstandard properties to the world, like toArray, without first prefixing them with an underscore.
• Change: NodeLists no longer inconsistently have array methods. Previously, live node lists would have indexOf, while static node lists would have them all. Now, they have no array methods at all, as is correct per the specification.