They're adding a bunch of new features and yet they ignore one of JavaScript's most glaring shortcomings: not tail call elimination. Honestly, I would be ecstat

They're adding a bunch of new features and yet they ignore one of JavaScript's most glaring shortcomings: not tail call elimination. Honestly, I would be ecstatic if this was the only change to the language. That said, I'm excited about some things. In particular, I really like proxies--being able to customize the behavior of your language (in this case, how objects work) transparently is a good way to decouple parts of your code. Now you can change how an object's properties behave without having to rewrite client code to use methods. Having modules built into the language would be nice too: having everybody use the same system for importing code will make life easier for everyone. The article mentions that sets "are an effective means of creating ordered list of values". Is this just a mistake on the author's part, or are sets actually to be ordered? Any sane set data type should not be ordered for two reasons: the obvious hash-based implementation isn't, and the actual abstraction (a mathematical set) isn't either. I believe that they are also planning to add more support for iterators over arrays, maps and sets, which wasn't covered in the blog post. I personally think this is a big mistake. In the recent past, I've had to use iterators pretty widely for a little project. (I was also using a coroutine system very similar to Python's generators.) I found iterators to be a horrible headache. They are essentially anti-functional: they introduce additional state even for benign things like iterating through a sequence! You can't pass them around, you can't use them twice, you have to be careful when writing functions over them... it's really not pleasant. Anyhow, some of the changes are certainly interesting--both in good ways and in bad ways. There's also always the question of how long it will take for enough browsers to support it. However, with the recent push towards automatically and quickly updating browsers, this shouldn't be as bad as in the past.