We've waited long enough for Java 7. Let's get that one out then look at the options. Fork Java, put the effort behind another language, like Go or Scala, or simply let Oracle run with it.
The Java programming language is only part of the story. There is also this thing called the Java Platform, aka the JVM. You can't just simply switch to Scala, your Scala code needs to be executed by something.
Yes, I am aware of the problems of this, too.
* Not as stable as the Java backend ever was
* Any code that used Java libraries explicitly needs to be rewritten
* Stallman is going to throw a hissy fit about it being .NET