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