13w36a (snapshot for 1.7) is pretty ****in epic. I recommend generating a new world with the "Amplified" setting. it generates terrain from bedrock all the way to sky cap, making huge sky islands and insane ravines. Tons of new items and about 12 new biome classifications (ice spike is my favorite as of yet).

anyone else tried this snapshot yet?

Yes i've been continuing in our older map with the new version (1.7.2). It took quite a while (in distance) before new biomes starting showing up haha.. Still haven't found a bunch but a few so far!