Looks like a nice mod to include. Given all the world generation features (including lots of additions to the nether), it might be best to add it when we update to 1.5.
I'm pretty sure natura is only for 1.5 anyways. There is a 1.47 'technically', but to use it, you need to rename some files from flora and fauna, which was what the mod was called at first.
sounds like a cool mod, but we have to reset the world before the trees and stuff spawn in the normal world.
This mod has been added to the test build for 1.5.2. We are currently testing world gen. I'm loving the new wood types.