In Duration and other parse methods, the syntax should be described using EBNF to remove ambiguity and allow automatic parsing and tools to be used efficiently.
Sounds like a fun task...
As a pure editorial item, it may be done after the API freeze.
Due to schedule and resources this is likely to be put off to a future revision.
The JBS 8019311 issue to tracking it is http://bugs.sun.com/view_bug.do?bug_id=8019311