For PC Minecraft players, Mojang will soon release a version 1.6 update that will add horses along with a few other features.
The 1.6 update, or the Horse Update, adds a number of mountable animals including horses, donkeys and mules. To protect your mounts, players can craft horse armor and lead/leashes.
In addition to horse related items, players can also craft carpets or use hardened clay, stained clay blocks of coal for other items. The addition of Hay bales will presumably feed your horses.
For increased accessibility, resource packs will replace texture packs. Resource packs will include the textures, sounds, language files, fonts and end credits without altering any of the Minecraft code. Mojang wants to eventually implement a system that makes every mod or plugin a resource pack to simplify the modification process and allow easier switching between a variety of mods.
Until the update releases, you can think or prepare ahead of time to make a stable for your horses or go even further to build a barn for a greater variety of animals.
Experienced players can download the 1.6 pre-release update on the website or wait until the official release on Monday, July 1st.
Source: Mojang