I can confirm that dropping in jna-3.4.1.jar (naming it jna-3.2.7.jar) works great on the Pi, at least under Raspbian. I unfortunately do not have a MacOS X machine to test against, as that was mentioned as an upgrade blocker. There are definitely more MacOS X users than Raspberry Pi users at the moment, so this isn't a high priority -- especially since all Java stuff starts slowly on the Pi (tens of seconds) anyway.
-Spencer
