Hmm, I think I’d add some more unusual animals. Eight legged horses and six legged chickens, for starters. No wolves, or coyotes, or mountain lions. I’d add plants that eat animals and non-toxic fog that comes in pretty colors, just to watch it mix and swirl around on windy days. I’d add spiders as big as cats that cannot bite because they only eat the pollen of flowers. I’d add flowers six feet across and let bats pollinate them instead of bees. I’d give people tails and make everybody’s genitals even bigger than they are now. People’s tails would be different according to their preference, and we would have to redesign chairs, but we could decorate them and braid them and do all sorts of things with our bushy tails to keep the hair stylists busy.
I’d leave the landscape alone, except I’d make quicksand slower, so that it would take a month to sink down far enough to die. That way, even the laziest person could wriggle his way out.
I’d make all the poisonous mushrooms with markings that were clear enough that you could tell the bad ones just by looking at them. I’d make plants that bore meat-like fruits so that no animals had to be harmed to satisfy the cravings of carnivores, and the vegetarian animal activists would have to get real jobs and stop being a pain in everybody’s ass. =)
Trees would be sentient and able to speak any human language, so that we could spend an afternoon sitting in a tree’s branches and have a wondrous conversation about the many wonderful things it had seen in its’ long life.
Damn, I need to go write some fantasy fiction about this subject now. =)