Except you don't run Java code, you run JVM byte code, and there are an increasing number of entertaining ways to do that without writing any Java.
The prospect of writing iStuff apps using Scala, Clojure (and one day I hope [J]Ruby) should be awfully appealing to innovative hobbyists, perhaps more so than using ObjC
Yes, it is, but it is currently not used for production.
Dalvik does not care about language, it converts java class files to dex file. However, Scala/Clojure/etc have runtimes with quite significant initialization time, that gets lost on desktop, but not on mobile devices. Scala is getting there with minimal runtime, but Clojure still initializes too much and the startup time of Clojure application on Android is atrocious.
The prospect of writing iStuff apps using Scala, Clojure (and one day I hope [J]Ruby) should be awfully appealing to innovative hobbyists, perhaps more so than using ObjC