The big changes I see in the future in Java 8 are the Java Module System (JSR 277) and Closures (JSR 335). The latter is needed to make Fork/Join more useable. Closures may have made a bigger impact a few years ago, but now with a plethora of other JVM languages, I feel this will no longer be the case.
What's becoming increasingly apparent is the increasing importance of Java platform. The important thing is not the Java language itself but the JVM. This acts as a substrate for different languages. Although from above the languages may seem different, it ensures that underneath the covers the the behaviour is consistent.
Some examples of JVM languages which have gained traction over the last few years are:
- Scala
- Groovy and its statically typed cousin Groovy++ (A great article outlining it's usefulness http://groovy.dzone.com/articles/sneak-peak-groovy-what-it-why)
- Clojure
- JRuby
- Ceylon, Red Hat's Java competitor
- CAL, a Haskell-inspired functional programming language.
- Gosu (programming language), an extensible type-system language compiled to Java bytecode.