currently there are 3 new biomes:
Greyforest
Vibrant Wastes
Sharp Plains (found in the nether)
1 new structure found in the greyforest:
dark castle
Two wood types:
Grey wood
Sharp wood
New Boss:
Super Creeper!
-immune to nearly everything
-drops a tnt core
New ores:
Iridium Ore
Ruby Ore
New plant:
Deadly nightshade
-drops a nightshade berry when broken
-dont eat it though... you'll regret it
-if you walk on the deadly nightshade you get the wither effect