The larger-sized iPhone rumor isn't new. It's been bandied about by Bloomberg in November of last year, and the Wall Street Journal in January.
Some have theorized that the smaller of the two would return to a summer launch, with the larger phone being the flagship, seeing an introduction in the more recently traditional September / October time. While many believe -- to compete with large-screened Android phablets -- a 5-inch+ iPhone is coming, analyst Ming-Chi Kuo of KGI Securities, who has proven quite accurate with regard to Apple's moves, disagrees.
Kuo instead argues that Apple will not create a 5-inch+ sized iPhone because of its "unwavering" dedication to the idea of easy one-handed use. Folks might recall that when the iPhone 5 was first introduced with its 4-inch screen, Apple aired ads saying it was the perfect size for one-handed use.
Sharp, Japan Display, and LG are all expected be sourced for the new display, in both sizes. In addition, Apple will have to up the resolution on the devices considerably in order to keep the so-called Retina display feature intact. The current iPhone sports a 326-ppi but that trails some rivals, such as the Galaxy S4 (441-ppi) badly. It's possible we might even see an FHD iPhone.
Other rumored features include a iPad mini-like design with a reduced bezel, a new sapphire-coated display, and possible camera upgrades. Naturally the new device(s) will see a processor bump, and as this is a non-S year, we'd expect many significant changes. That might, though, be encompassed by the size increase.