Apple notoriously applies for tons of patents, very few of which will make it into actual products. This one is interesting from a UI perspective.
You could argue either way, but let's say it's an ergonomic necessity to have an easy-to-locate Home button, as now exists on the iPhone. That button cuts into screen real estate. Is there a way for Apple to get rid of it, growing the screen, while still somehow offering the Home button's functionality?
The answer may lie in a patent Apple has secured involving the measuring of electrical capacitance of the body of a product. As an example, if this were incorporated in an all-screen iPhone, the user could simply squeeze the phone's housing as a means of input. That doesn't mean the body of the phone itself would have to deform; it just means that the phone's body would register the change in capacitance coming from a squeeze, and would turn that into some sort of command. Software would sort out whether the squeeze was purposeful or accidental.
Apple Insider is speculating that the technology mentioned in the patent, which was granted several years ago, may pop up in the forthcoming iWatch.