First of all the water mobs spawn on land and then die themselves no matter how hard you push them they just keep swimming in air like dolphins on sand and a shoal of fishes in a swamp.
Second known bug is that campfires don't cook food at all, they are just deco blocks now.
Campfires do cook food, just not the minecraft way. You kind of have to lure the mobs to the campfire and let them burn to death. As for water mobs....err, that is being worked on, but is still buggy for now. Hey, free food when the fish die.
@Arkatron: water mobs that end up on land can be pushed in water, then punched down to enter the water. :P It's not really nice, but it works.