Python is doing very well, and the really good thing about established languages is that their pros and cons are known. Not many people would choose Python to write a high-performance server or a program that's expected to grow to a million lines or so, and if they do, they have no one but themselves to blame. With newer or less popular languages, you might not know what you're really getting yourself into, and if, five or seven years in, you end up not where you wanted, well, you also have no one but yourself to blame.