One of the devs here. It's definitely not intended to be a new language. My understanding is "text/traceur" was chosen because some of the features haven't been

One of the devs here. It's definitely not intended to be a new language. My understanding is "text/traceur" was chosen because some of the features haven't been accepted officially into harmony yet (i.e. they are strawman proposals: http://wiki.ecmascript.org/doku.php?id=strawman:strawman http://wiki.ecmascript.org/doku.php?id=strawman:strawman), in particular classes/traits and async.