>From what I've read (and is repeated here: http://en.wikipedia.org/wiki/Dalvik_virtual_machine), Dalvik has its own bytecodes suitable for a register-based VM. I haven't heard that it can read Java class files (regardless of the source) directly; I believe you have to convert them using the dex converter tool.
Even though Android source looks like Java (with some JDK classes unavailable), for the purposes of Jini, it seems more like just another foreign language which would need a surrogate to communicate with Java-based Jini services, no? Patrick
