HTML5 classList API

Having thrust myself into the world of JavaScript and JavaScript Libraries, I've often wondered: When are browser vendors going to see the helper methods/libraries created by the JavaScript toolkits and implement these functionalities natively within the browser? I realize that standards are important and browser vendors can't afford to half-ass these implementations but I do believe they could be...expedited.  The good news is that one of these functionalities has been add to the HTML5 API; classList.

The classList object, added to all nodes within the DOM, provides developers methods by which to add, remove, and toggle CSS classes on a node.  classList also allows developers to check if a CSS class has been assigned to a given node.