[DarkHoodness]

I've been playing around with MC edit for the first time today - As I've said before, when Minecraft 1.0 gets released, I'm thinking we should start a new map but import our structures (or rather, the entire chunks that they're on - meaning we can keep what's under them too) across to it. That way we get to keep what we've built, but we'll be able to find mushroom biomes, snow biomes (which don't exist in 1.8) and hopefully strongholds out in the wilderness - Although it'll be at the cost of our existing wilderness.

MC edit is a little tricky to use but it is quite possible to transfer our stuff across to a new map - With a little extra work, it's also possible to carefully blend out the seams between old and new chunks too.

EDIT: However there is the small problem of 1.7 sea level being 1 square higher than 1.8 sea level. Also underground - You'll find 1.8 ravines being suddenly blocked off with a huge wall where it meets an old chunk - Sometimes with a 1.7 cave system making holes throughout that wall. I think that's a small price to pay for being able to have the new features in the wilderness, though.

The nether is editable as well, BTW - So we'll also be able to keep parts of that. Oh, and any chests that get imported from an old world will keep their contents. Same goes for signs. Player inventories can't be kept though - So people would have to deposit their stuff into chests before the new map is made.