the bad points are that by the time the mod actually gets mature it will have lost most of the original people because it changed too much, and you'll be back to the point where no new people can come in because now it's matured to the point where it's too complicated for some newbie to learn it.
with good developers like ss and maybe a more experienced mod coder (no offence ss!) and more importantly some good dedicated artists, there's no reason it shouldn't be done fairly quickly and get out there as a mod early in the game's life, much like wfa.
I think everyone knows the mods that come out 2 weeks after a game's release are crap anyway, no one will care about em.