Good news for you, Millénaire come with an installer that removes the requirement of manually editing the jar ;)

Shameless Minecraft-related plug: I'm the author of Millénaire, a Minecraft mod that ads NPC villages of multiple cultures that collect resources, extend their villages, trade with the player, and since recently give quests to the player. Have a look, it gives new aims to Minecraft. http://millenaire.org/

A little blatant self-publicity there, but at least it's very much on-topic: the Millénaire mod (http://www.millenaire.org) already includes NPC villages for Minecraft, with NPCs that expend their villages, trade with the player, have children who get new jobs, produce new types of food and items, etc. They have a wide range of possible buildings too, and players can easily add their own plans to the mod. NPCs currently to either medieval Norman or medieval (Asian) Indian cultures.

Forgot the disclaimer: I made that Millénaire mod.

That village was decent-looking, but no villagers? I suspect whatever villagers he has time to make before release will be very passive. Certainly far from those of the Millénaire mod (www.millenaire.org), that expend their village, improve buildings, have children that grow up into various kinds of adults, trade with the player, etc.