Forget the home button. It looks like Apple's planning on squishy displays with buttons underneath, according to the latest patent they've been granted.
U.S Patent No. 8,816,977 covers "Electronic devices with flexible displays" and describes a system where a flexible layer is placed above buttons, switches or even speakers. Internal actuators could be put in place to create temporary input shapes such as buttons as needed by a specific application, allowing Apple (or presumably those who licence the patent) to develop systems with larger space available for displays rather than controls.