Still not full HD
The new display resolution is likely because of the new size options the iPhone 6 is rumoured to have. It’s also likely a response to all the Android phones out there with “full HD” 1080p displays, though the new rumored resolution still isn’t 1080p. Of course, as with all the new screen resolutions that have been introduced over the years, this will require developers to rewrite their apps to support it.
Going further into rumour territory, iOS 8 supposedly will feature up to five horizontal icons with this new resolution but the only source we have on that one right now is China’s slightly dubious Weibo.