It looks like another potential "successor" to Java is on the horizon, with a Red Hat software engineer working on a language called Ceylon, which purports to fix the problems of Java but still run on the Java Virtual Machine.
Under development by Gavin King, a JBoss Fellow at Red Hat, Ceylon is intended leverage the successes of Java while correcting its supposed failures. In presentation slides found online, King describes the goals for his new language: It would run on the JVM and feature static typing, automatic memory management, and built-in modularity. It also would strive to be easy to learn.
Ceylon arose out of frustrations with Java, such as it "being joined at the hip to XML" -- which King said hurts developers -- and the absence of a good way to design a user interface in Java. A lack of language-level modularity and issues in Java meta-programming were also cited. Frustration with the Java SE (Standard Edition) SDK is a problem, as well; King says the SDK lacks modernization, is bloated, and makes basic tasks difficult to accomplish.