If you want to know the schedule and/or the scope of Java 7, David Flanagan's posting to java.net is very informative.
Apparently we will have to wait a little bit longer for Java closures.
2009, really? Two more years?
If Eclipse IDE support were just a little bit better [1], Scala could become a true option, even for db4o core development. Scala compiles to Java ( and sometimes to .NET IL ) so it would work to start with some libraries in Scala.[1] There is a Scala Eclipse Plugin, it works OK, but it's missing code navigation, autocompletion and refactorings.