Yeah, yeah. I know. It's only been recently that Erlang has started being touted as "the next Java". I just thought I'd get a jump on crowning the next next Java. Oh, sure, no one gets to officially be The Next Anything without a Pragmatic Bookshelf book backing it, but I'm sure it's just a matter of time before a Scala book is announced.
After all, Scala shares a lot of the advantages of Erlang -- principally, its support for Actor-based concurrent programming and hence its powers of super-scaling. But it also has a secret weapon that Erlang doesn't have: it runs on the JVM! Yes, that JVM! It also has access to the multitudinous multitudes of existing Java libraries out there, making for a (potentially) easier migration path.
No need to wait for Java 7 (or (possibly much (much)) greater) for closures in Java! Write some Scala scaffolding around your existing Java classes and have them today!
Le roi mort! Vive le roi!