Terraria 2 currently in the planning stages, says creator

Terraria 2 will definitely be a thing, but it's not in development just yet, according to creator Andrew Spinks. While the follow-up is still "a ways out," Spinks told RPS that it will have a few things in common with the original, but will be different as well. Some of the returning features will include "the way loot, and progression works" but with the sequel, he wants to include "infinite worlds so you're not just stuck to one world. You can travel anywhere. I want more biome diversity in that, too." Those still playing the original, which was recently updated to version 1.2, can look forward to "endgame progression within the next month or two," and more updates may be coming down the line.