Aside from the obvious that just about everything will go away someday, is there a reason you believe this?

From my vantage point (albiet limited) python looks like it has staying power. It is easy to use, effecient enough (and with unladen swallow in development it may get a lot more effecient soon), and currently seems to be gaining ground instead of losing. Eventually I am sure that it and any other language you can possibly name will get supplanted, but I am not aware of any particular reason to expect that any time remotely soon.