To my knowledge, the original phrase was intended to make the new king throned immediately after the discovery of the death of the previous king. Unfortunately there's no real atomicity in spoken language ...
As far as the idiom is concerned, it makes perfect sense if you think about the second usage as the set of problems for which the language is commonly used to solve. Take for example JavaScript:
Javascript (the original language) is dead. Long live Javascript (the successor language for the problem of client-side scripting).
This would be a great title for an article about a scripting language like coffeescript