I'm not an Apple user (nor fan), so I didn't follow the development you made. Actually, I don't really understand the point, or what it allows you to do.
My (too simple?) view is that you already have the choice of using either Eclipse or Processing as an IDE, and that's more than enough. I don't want to spend too much time in "creating better tools" especially if I'm the only one to use them, and I'm not proficient with Eclipse, so I was attracted to the Arduino/Wiring/Processing approach as it allows me to focus on the task at hand. No need to handle 50 dependencies, makefiles, gcc parameters, mappings etc, it's already difficult/stupid enough to separate the "" and the <> libraries ;-)
Could you tell me in a few words why Mcode was so attractive, and what you find good in Netbeans and bad in Wiring/Arduino ? Maybe it's my hammer and all the boards are nails to me ? It wish they were : imagine a world where sketches would be portable between AVR, Cortex, PIC32 etc. THAT would be nice for me.