(Can't bump a sticky, so I might as well flood new info when it comes out, m'kay?)
Snapshot. Wow.
A new dirt type, "Packed Ice" (appears to not melt near light sources but is not transparent either), EIGHT NEW FLOWERS, WAIT MAKE THAT 11 NEW FLOWERS, two new grasses, three new fish, two new enchants (Lure and Luck Of The Sea), potions of water breathing, and... oh my god.
Terrain generation has an "AMPLIFIED" option.
Yes, terrain finally naturally generates above the old 128 limit,
at least with this optional world type, and it pretty much turns all the normal biomes into "extreme hills", and turns the previously-mountainous biomes into crazy floating landmass type stuff.
When you land from a big jump, particles of whatever you hit fly out. Works properly with wool colors, though grass shows dirt particles. It only happens if the fall is big enough to cause fall damage, and the further you fall the more particles are made and the more violently they're expelled.
They got rid of the ugly swamp colors (changed to a less-ugly color).
There's naturally-generating giant mushrooms outside of the mushroom biome.
FAT TREES.
All the above screenshots were taken with an AMPLIFIED world type.... of course the normal world type is more reasonable as usual.
New rocky outcropping land formations, spruce trees that generate outside of snow (and there's new mixed-tree forests).
Okay, enough info for now.