What I like most about Java is that you can switch more easily to certain fashionable languages (Scala and Clojure) which have good interopability with Java because they use the JVM.
Counterpoints:
Couldn't find any data on how well Clojure works with Java apps.
Scala's decent interoperability appears to stem from a Maven plugin rather than directly from its ability to use the JVM.
Clojure's Java interoperability is better than Scala's. For example, Java collections are automatically treated as Clojure collections with no wrapping required, any Iterable is a seq etc.
Sources for this claim: http://www.slideshare.net/tackers/how-we-mostly-moved-from-j... http://java.dzone.com/articles/moving-java-scala-one-year
Counterpoints: Couldn't find any data on how well Clojure works with Java apps. Scala's decent interoperability appears to stem from a Maven plugin rather than directly from its ability to use the JVM.