There are many great (and long overdue) features coming in Java8. Amongst those are the new Date/Time API, interface enhancements, additions to both concurrency and NIO and miscellaneous helper methods on String and Collections.
The ‘List of Java8 features’ link provides a very good overview of the changes. The video does a great job of demonstrating the functional additions to Java8, and their benefits. Lambdas (syntactic sugar for functional interfaces), interface improvements, Streams and Collection enhancements, as well as the introduction of Optional.
This brings Java8 closer to the other common JVM languages. It still isn’t as powerful functionally as Groovy or Scala, but at least it’s a really good step in the right direction.
One limitation of Java8 is one can only define a Lambda that takes at most 2 parameters. There are other weaknesses, but overall, some powerful additions.
Live Coding Java8: http://parleys.com/play/52a4b5cfe4b0e619540cc470/chapter0/about
List of Java8 features: http://www.techempower.com/blog/2013/03/26/everything-about-java-8/