i actually haven't found too many problems... once i saw it rain inside a cave through the roof... being able to build directly within the game/server spawn point is completely broken, but i remember that being broken in 1.7.x too.
I haven't seen random fake sink holes show up like 1.7.x used to.
The new ender men are a little disappointing... too few to make them moving blocks a problem, they sound like zombies when attacked, and they don't put up much of a fight. I'm guessing this will be fix/tweaked as 1.8 progresses.
water behavior is a little bit better.
they introduced a "hunger" meter where if you go too long without eating, your health will start to go down as if you're drowning. Running and swiming seems to make your hunger bar go down faster. However, when you eat, your hunger bar goes up, but your health does not... at least immediately... once your hunger bar is above a certain point, your health starts to slowly regenerate. Not sure how to directly improve health yet. Also, when your hunger bar is near full, i fyou hit the UP arrow key twice, you will start to run a lot faster than normal speed.
the biomes are a lot more varied and nicer looking. New ones i've noticed are marshes and plains. Sunrise and Sunset look nicer too.
I've seen what looks like the mineshafts they've talked about, but haven't explored down to investigate yet... I've also found the randomly generated towns, but without mob NPC's, it seems kinda dumb to have it there and empty, except if you are first starting out and you are lucky to find one, it's nice to have a place with already made buildings, torches, etc right there.
So far, i haven't found the new beta unplayable and it's been fun to find all the new stuff they've added.
