Most of the projects I try to jumpstart are community builds, and they are very hard to run effectively. I'm incredibally surprised how well Bushido's Collab city went, because that crap got finished in a few weeks and it was huge (and there was always progress being made, even with as many people goofing off as there were) Out of the tons of community projects I have tried to start in my years of Blockland, I think there was only one or two that even got to 3/4ths of the way done.
I do agree though, I love community projects and I wish there were more of them. Not just things like Badspot's Block Party or Wedge's BYOB (Which I do love as well) but more things like Bushi and Eksi's Collab City.