Those rumors in March were spawned by a questionable South Korean news outlet that no one's ever heard of before, and I quickly shot down why the iPhone simply wouldn't sport a 4.6-inch display. I had concluded with the admission that rumors of a 4-inch screen are more believable.
Those 4-inch rumors are back, and this time we have the reputable Wall Street Journal throwing its hat into the rumor ring, saying that Apple is boosting its screen real estate from the current 3.5-inch flavor up to 4 inches. The report says Apple is currently working with a handful of display makers, including LG Display
Samsung's smartphones have taken off in popularity lately, with both researchers IDC and Gartner naming it as the top phone maker in the world. Sammy has been pushing the envelope with screen sizes, like the 4.8-inch Galaxy S III, the 4.65-inch Galaxy Nexus, or the monstrous 5.3-inch Galaxy Note. Those dimensions suggest that maybe consumer tastes are trending larger.
A side note of interest to Universal Display
The iPhone has carried a 3.5-inch display for the past five generations, so a change may be in store, and I think this has a very good chance of happening. The biggest question will be how Apple handles the screen resolution. Introducing a new resolution and keeping the pixel density the same would threaten to fragment iOS, which is Apple has always pegged as Google
I think Apple would choose to keep the same 960 x 640 resolution but will need to reduce the density from 326 pixels per inch, or ppi, to 288 ppi. That would still be higher than the third-generation iPad's 264 ppi, although Apple's "Retina" marketing approach there was that the iPad is typically viewed from a further distance.
Apple's marketing department has worked wonders before, so I expect it will still come up with some way to still call a larger screen with the same pixel density "Retina."
Everyone wants a piece of The Next Trillion-Dollar Revolution, including Apple and Sammy. Another company is also trying to ride the wave of mobility from the inside. Grab yourself a free copy of this report to find out more.