What are the differences between the corruption and the crimson

The 1.2 patch of terraria introduced an alternate biome to the corruption called the crimson. What are the differences between the two?

Solution 1:

Crimson appears to be a substitute to the Corruption. The first world I created after installing the 1.2 update contained a Crimson biome, which also happened to take over a neighboring desert. Various differences with Crimson include:

• Crimstone replaces stone
• Crimsand replaces sand
• Crimtane Ore replaces Demonite Ore
• Crimson Altars replace Demon Altars
• Demon Hearts replace Shadow Orbs
• A few unique item drops
• A few unique enemies (Blood Crawler, Face Monster)
• A unique boss (Brain of Cthulhu)

Otherwise, I'm pretty sure Crimson can essentially be considered an equivalent to Corruption (it appears to spread over time in the same fashion, for example).