Don't you want to know whether the next iPhone would pack a super-high resolution display panel or not? Well, it seems that the latter valid in this case. The new Xcode 6 SDK hints that the iPhone 6 has a display resolution of 1472 x 828 pixels, which is just above 720p, but far lesser than a 1080p display.
You have to keep in mind that we are talking about a 4.7-inch display here, for which 720p is usually good enough. However, we are a generation that has been spoilt by 1080p phones at the same size (HTC One M7, remember?), so that's that.
However, it is unlikely that the odd screen resolution, and also that it isn't 1080p, would affect the sales of the iPhone 6 at all. iFans be like... whaat? Retina display!