The Apple iPhone 4 will be available on Verizon February 10. According to Engadget, the location of the mute button on Verizon iPhone 4 has shifted down a tiny notch, which means it will affect some existing iPhone 4 cases. Apparently the Apple store has already introduced a modified, universal design for its iPhone 4 bumpers. The cutout for the mute button is larger to fit both AT&T and Verizon iPhones. This is something to keep in mind when you shop for a new iPhone case.