but reading the futur v4 specification for ECMAscript, they clearly want to move the language to a Class-based language

and imho that's not a good thing

ECMAscript is powerfull when you can use expando and adapt the language defaults to your needs

date.prototype.format = function() {...}

THAT is powerfull, you can't do that in PHP for example

it will be sad to cut that particular way of doing Object Oriented Programming