Not grumpy at all. Of course you are right but solving this problem and making features like this available in dynamically typed languages is a bit tougher and

Not grumpy at all. Of course you are right but solving this problem and making features like this available in dynamically typed languages is a bit tougher and in some cases, not at all possible as certain things might only be known at runtime. So intellisense news in an IDE is certainly nothing new but it is "newish" for more functional/dynamic languages like JS. JetBrains has also done a good job with their intellisense in their IDEs for Python and Ruby, for example.