* Add more options to mapshow.
* Implement support for projections. I (current mapping pkg maintainer) have little need nor much experience with this subject => help welcome!
* Add geodesy functions. Patches have been submitted but not yet integrated. A suggested roadmap would be to integrate Felipe Nievinsky's geodesy toolbox as an upstream dependency but that toolbox needs documentation work.
Several functions in the current mapping package release (1.2.1) haven't had much testing. Please try them out and report issues in the bug tracker with "[octave forge] (mapping)" tag in the title.