We have known for a while that Minecarts would arrive in Minecraft Pocket Edition 0.8.0, but today our first peek at them in-game has been revealed. Today Johan, a developer of Minecraft PE, tweeted the above screenshot with the caption "Minecarts are working!" Also visible int the screenshot are normal and powered rails, but there is no redstone powering it. It's fairly obvious that some bugs need to be worked out by looking at the screenshot, as the player's head is rotated 180 degrees instead of his body. But at least it's a start!
Source: Twitter