http://dev.bukkit.org/bukkit-plugins/mcmmo/
I think that adding the MCMMO plugin to the server would make the survival aspect a lot more fun, allowing people to level up in mining, archery, etc, would make the survival world a lot more fun to play in for existing members, returning members and new members.
I've played on servers with this, and find it so much more fun in survival than without this, as the skills have leaderboards and people can compete to get high on the leaderboard, thus spending more time online etc.
We'd be able to disable or enable it in particular worlds, so it wouldn't effect PVP etc, and only be active in survival.