Apple's newest iteration of its classic home button sports an integrated metal support bracket, which we hope will greatly strengthen the oft-used switch.
Many iPhone 4 and 4S users have experienced the woes of a faulty home button, but haven't been brave enough to attempt the repair. This new design should not only increase longevity, but also make replacing the home button a lot less of a hassle.
A side-by-side comparison of the iPhone 4 and iPhone 5 display assemblies. The iPhone 4s has an integrated home button.