I've now published a third go at this, in
http://sourceforge.net/projects/gretl/files/osx-testing/
On OS X 10.6.8, at least, it fixes some (not all) of the issues
mentioned by Henrique and Berend. Among other things, there's
support for the R shared library and there's a window listing under
the top-level Mac Window menu. Some of the keyboard accelerators are
better than before.
Allin