The roofed forest biome seems to have very thick, nice trees. It also has tall mushrooms that grow randomly in it. It looks pretty darn awesome.
BTW, the amplified terrain gen option seems to generate terrain normally, just it makes it way more weird looking. It generates giant mountains with overhangs and cliffs that go waaaay up in the air. It looks strange, but is actually kinda cool.
It gives a good head start when playing Survival too
Many new flowers including: Poppy, Blue Orchid, Allium, Azure Bluet, Red Tulip, Pink Tulip, White Tulip, Orange Tulip, Oxeye Daisy, Sunflower, Lilac, Double Tallgrass, Large Fern, Peony, Rose Bush (Where did regular roses go...)
Packed Ice, you cannot see through it like normal ice
2 new enchants for fishing rods which are named Lure and Luck of The Sea which can be up to level III enchants
3 new fish: Salmon, Pufferfish, and Clownfish
New fishing style, the fish have bubbles where they are in the water and they'll swim to your lure and pull it down. You basically know when it'll happen now and not randomly.
New jukebox disc called: Wait
New Biomes: Taiga, Savanna, Mega Taiga, Swampland (Shrek), Extreme Hills+, Roofed Forest
Giant mushrooms spawn in Roofed Forest biomes.
Eating Pufferfish gives Nausea II, Posion IV, Hunger III
You can initiate running by simply pressing CTRL now
New potion: Potion of Water Breathing
Total revamp on the settings system which I'm loving
Love the new snapshot! Runs much cleaner and the fact that snow biomes and desert biomes won't spawn next to each other it a HUGE improvemt. Keep it up Mojang! Keep going in this direction and Minecraft will rise in eternal glory
Glad this has been rectified. Always annoyed me...