Can anything really be gleaned from the fluctuation of a language on TIOBE? Two years ago, Apache Groovy wasn't even in the top 50. Last December, it ascended to #11. Now it's at #31. Whatever the story was, it's too opaque to interpret.
Java will decline because (1) so many hate on it, (2) there's always the new shiny, (3) Microsoft will never give up. No single language will replace it, though. At least not for a long time.
