Go read Daniel Spiewak‘s excellent blog series about Scala. With Scala you can keep:
- all your Java libraries
- all the advantages of running on a JVM (ubiquity, administrative tools, profiling, garbage collection etc)
But you can write Scala code:
- more concise and clear than Java (especially using more functional style, such as in the collections library)
- it has closures and functions as part of the language
- it has operator overloading (from the perspective of usage)
- it has mixins (i.e. interfaces which contain implementation)