Today, Minecraft was updated to version 1.7.2. The update is being called "the update that changed the world" and introduces plenty of new biomes, stained glass, new wood types, new flowers, new fish, and tons more. The full changelog is below.

Changelog for Minecraft v1.7.2 (includes 1.7 & 1.7.1) for October 25, 2013


You can purchase Minecraft (if you somehow don't have it yet) and run the launcher to grab the latest update.