The software is great. It has few great features like the possibility to pre-download maps along a planned route so that you won't walk in the dark if you happen to be without Internet coverage.
What I would like to see (and may be I'll do it myself) is to use the GMaps APIs when Internet is available during the trip and to switch back to the cached jpgs when not.
GMaps APIs do not provide (as far as I know) a way to cache maps, but Maemo Mappe already stores the maps downloaded along the way.
I did not try the patched versions yet, but I'd like to see many of them integrated in the main project. The screen size of the Nokia 770 is quite big, there's enough space to show more infos (current speed, altitude, GPS signal strength and so forth).
I was planning to do something similar to Maemo Mapper for my Symbian OS/UIQ phone (the Motorola A1000) but developing for Symbian is like developing on Windows: a nightmare.
This is Linux. I was born on Linux and my father (the virtual one :-) ) gave me the keys for VI.
Let's see what the future will say.
UPDATE: well, something is already working on it: