In early December, Mojang's Daniel Kaplan announced via the Mojang blog that the developer was working on an update to Minecraft Pocket Edition in order to address player concerns that the experience was too different from its desktop counterparts, specifically the distinct lack of any survival or crafting elements.
While the crafting system will require UI redesigns, Kaplan says that the first update, currently scheduled to go live on February 8, will make backend changes to "support the survival aspects of the game." It doesn't sound like any survival elements will actually be implemented this time around, but rather that this update will serve as the "foundation" for survival elements that will be added in later.
The update also includes "neat looking animals and new blocks," as well as doors and fences, so now might be a good time to start building the farm you'll be furiously defending once the survival elements are patched in.