When you recode it set it in a way that allows the slower mechanisms to work. The really fast ones caused huge amounts of lag. A slower one that's a lot bigger could replace it.
Bukkit is an API. As such, it should leave game mechanic changing decisions up to server hosts to implement in the form of a plugin. A plugin already exists to prevent sand duplication from being possible. If a host wants to run a vanilla PVP anarchy server, sand generators and all, then they should be able to do so.
