__proto__ is likely going to be in the ES6 spec as at least normative optional. Recent discussions indicated there's some chance it will become full-fledged part of the spec.
http://wiki.ecmascript.org/doku.php?id=strawman:magic_proto_property https://mail.mozilla.org/pipermail/es-discuss/2012-May/022842.html On Friday, June 8, 2012 8:35:12 AM UTC-4, Tim Smart wrote: > > __proto__ is marked for depreciation in upcoming ecmascript specs. I think > that is the most common reason you might find. > > Tim. > >