Kinda reminds me of opening up Rachel Temple in Ragnarok Online. I think the entire server had to donate about 50,000,000 zenny before it became available, but you could only donate after you went through this pretty lengthy quest chain. Having played on a private server with a population of around 300-500, well, needless to say it took us a while, haha!

Directly on-topic though, I like the idea, but I also have to agree with Tiggy: once it's done, it's done, and even if people could continue to do quests in the name of 'general upkeep', I don't think as many people would. I'm already getting that vibe from the Beastmen dailies. Once everyone finishes those up again, we'll be stuck with a barren Zanr'ak and Slyphlands.