I just tried all features in the snapshot. It's awesome. Horse is fast and also can jump. I like the fact that horse can climb 1 high block with out jumping. Leashes working fine and carpets are good addition but I don't find any use of it yet. Now I have one more think to build in Minecraft.
For all of you who wish to understand a bit about the horses:
-Currently no sound, but they look adorable.
-I counted seven types of horse.
-They eat apples and wheat, that's how you tame them.
-They need a saddle to move, but you can sit on them after they're tamed.
-Grown horses take five hits from an iron sword. Baby ones take three.
-They can be armored with iron, gold and diamond. I have yet to figure out the recipes.
-Horses have a grass-eating animations, like sheep.
-When mounted, the health bar remains the same. However, the food bar is replaced with another one I don't understand.
-The experience bar is replaced with a charge bar. Release it at it's peak to make your horse jump two blocks.
-Horses can hop one-block-high obstacles without jumping.
-You can attack while on the horse.
-You cannot attack the horse when you are on it.
-They are extremely fast and a bit glitchy at times.
I hope this helped you all out.
I am writing this from the back of my horse.
The replacement for the hunger bar is the Horse Health Bar. you can also tame them with Bread and Sugar.
Here, found out how to tame a horse. Feed it and keep trying to put a rope on it, once it goes on the horse, put a saddle on it. Edit: Or just feed it and get on it, if it keeps bucking you off, then you gotta feed it more. They eat apples, golden apples, wheat, and bread. Surprisingly, they won't eat carrots.