Does anyone know what the browsers' plans are for implementing this? Hopefully the next major version of Chrome, FF, and IE have it (properly) implemented. Until then, it is hard to get excited as it will likely be quite awhile before it's ubiquitous.
In summary, some Mozilla JS extensions from Firefox 3.0 have been adopted into ECMAScript. Some ECMAScript 5 APIs have been added to Firefox 3.5, but not all of them. All the browser vendors have put a lot of effort into ECMAScript 5, so I'd expect they're willing to actually implement it, too.
