Here is my prediction: it will take academia 10 years to stop teaching Java 1.2 and start teaching, say, Scala. It will then take industry about 20 years to realize that Java is not "the best" anymore.

So for 30 years, everything other than Java 1.6 and C# will be "niche".

(Sure, there are plenty of non-Java shops around. But anywhere where software is not the primary concern, it's the default. It got that way because of marketing and an easy word to Google, not due to any technical merits. So the new languages that are competing on technical merits are probably not going to win in industry, only among the handful of programmers with a clue. Just sayin'.)