Two major updates are coming to Minecraft Pocket Edition in the near future. The first update, 0.8.0 (coming late this month/early December) will add minecarts, rails, more foods, improved mob AI, and much more. Minecraft Pocket Edition 0.9.0, scheduled for the first quarter of 2014 (Jan-April), will add tall grass, caves, new biomes, and much much more.
Mojang also has said they plan on adding more mobs in Pocket Edition 0.9.0. Today, one of the new mobs has been revealed: the enderman! That's right, that tall scary mob that takes blocks out of the ground and off your structures is coming to Pocket Edition! Pocket Edition developer Tommaso Checchi revealed on Reddit the new mob yesterday. See the source link for his original comment.
Artwork by Malliya on DeviantART.