Haha I'd be interested in helping out with this as well if I weren't as busy as I have been lately.
Solarus' new quest editor (Qt based C++ as opposed to Java like the original) is quite nice; perhaps there's something to be learned from it that would assist the development
of FFC's map editor? I know you complained about the code he wrote for the Solarus engine itself before, but oh well haha.
At the very least, as usual, I'd really like to see internationalization support so that users would be able to contribute translations to different languages. Solarus' quest editor has this. (^_^;)