Many websites are flooded with the news on a possible leak of the the making of iPhone 5 displays. One of the things noticed in the image that shows that they aren’t the iPhone 4 is the larger shaped home button. It may also not be the iPhone 5 but it does prove that another handset is on the way.
The Wintek plant that is manufacturing the screens, is also responsible for manufacturing the touchscreen iPhone 4 screens. Perhaps the iPhone 5 or another type of iPhone 4 is in production?