So we seem to be entering the phase of the rumor cycle in which we start to get leaked photos. In this case, the photos aren't of the iPhone 6 itself but of the mold that's said to be used to create the back casing.
According to AppleInsider, the mold suggests that the iPhone 6 will indeed have a 4.7-inch display. The image accompanying this post shows an iPhone 4s superimposed on the photo of the mold to give you a sense the relative size. An earlier post on AppleInsider also showed leaked images of alleged schematic drawings of the device that originated from Foxconn, which manufactures Apple's iPhones. The schematic shows an extremely thin, tapered device with the same chamfered edges used in Apple's most recent products.
All the rumors continue to suggest that we'll see a 4.7-inch iPhone 6 in September and a 5.5-inch "phablet" later in the year.