Minecraft - Pocket Edition may have one of the slowest development timelines around. Of course, the main reason we accept this almost Valve-ian wait is because every time we do get an update, it brings awesome stuff like friggin' Zombie Pigmen. Oh yeah, and the Nether Reactor that summons them, which is exclusive to the Pocket Edition. Heck yes.
The update also brings a few other new features, like paintings and mushroom farming. In addition, several bugs have been fixed. Here's the full changelog for your perusal: