Hey guys, I was looking at the renewable resources page and it says that as of 12w06a (current or latest is 12w08a) zombies will drop iron, which means that we will have a bounty of iron with zombies.
Also, water is suppoused to be renewable as of 12w06a as well, although I'm not sure if that simply means we can take from running water as well. Lava isn't renewable just yet, which would be nice for smelting purposes...