Reddit user MC_Pitman has spent the past year revamping terrain generation in Minecraft and, judging by the results in the image above (make sure you click in the top-right to go full screen), it's time well spent.
The aim of the project was to make terrain regeneration look "more natural and realistic...more like a generated landscape than a bunch of individual biomes", they said on Reddit. They've built a big world with a number of zones—the one you see above is the Alpine climate zone, which MC_Pitman says is the "most polished and complete" sector. The way the different environments meld together is gorgeous, and I'd love to build a house atop that hill in the centre.
A first release of the full world will be available "in the next few months", they said.