The ES6 spec draft is in its final stages of being revised. At this point there shouldn't be any substantial developer-facing changes except to a few final things that are being ironed out (mainly modules).
The features that are being shipped in Firefox are ones that are stable in the draft spec and not expected to change. At the point of spec stability, these features need to be actually tested in broader distribution to help find any potential compatibility corner cases, similar to the issues found with Array.prototype.values [1].
The features that are being shipped in Firefox are ones that are stable in the draft spec and not expected to change. At the point of spec stability, these features need to be actually tested in broader distribution to help find any potential compatibility corner cases, similar to the issues found with Array.prototype.values [1].
[1] http://www.esdiscuss.org/topic/array-prototype-values-breaks...