I just made a new 1.1.1 world, to see if I'd get a nice little snow biome.
Low and behold, do a bit of initial exploring, and I do. What is better? It's butted RIGHT next to a Jungle Biome. The Jungle has a Corruption on the far far end of it.
I think that by building in the Snow and Jungle biomes, my home will be plenty safe from any evilness coming from post-WoF Corruption and Hallowed biomes, since neither Jungle or Snow can be corrupted or hallowed.
Anyone else got some cool new worlds, possibly with great little safety pockets like this?