Reuters confirms 4-inch screen on next iPhone
The new iPhone screens will measure 4 inches from corner to corner, one source said. That would represent a roughly 30 percent increase in viewing area, assuming Apple keeps other dimensions proportional. Apple has used a 3.5-inch screen since introducing the iPhone in 2007.
Yet another report that indicates Apple is indeed planning to launch a 4-inch iPhone later this year.

The new iPhone screens will measure 4 inches from corner to corner, one source said. That would represent a roughly 30 percent increase in viewing area, assuming Apple keeps other dimensions proportional. Apple has used a 3.5-inch screen since introducing the iPhone in 2007.