It's not due as much to deep differences in syntax, as to the available time. SE2012 was heavily front-loaded with a lot of work for the generic pieces of the beautifier engine and related boilerplate, so C++ and Obj-C was all we could fit into the schedule.
Now that the basics are already in, adding Java into SE2013 has been mostly a matter of just addressing the differences between our "common to most brace languages" module, and additional syntax in Java. So it's going pretty quickly.
