More evidence has emerged suggesting that Apple will be coming out with an iPhone 6 that has a 4.7- or 4.8-inch display, as well as a "phablet" with a 5.5-inch display. The most recent rumors come from a post on BGR, which cites a report from a South Korean securities firm known for having inside sources. BGR says there have now been at least a dozen independent reports of these larger screen sizes. However, this recent report goes well beyond giving the screen sizes and offers details on the other specs. They say the iPhone 6 will have HD resolution of 1,920 x 1,080 pixels and that the phablet will be a 2K device, with 2,272 x 1,280 pixels. Unlike the 5s, they say the iPhone 6 will have a 128GB option, in addition to 16, 32, and 64. Other specs for the new phone are similar to the 5s, including an 8-megapixel camera and a 3.2-megapixel FaceTime camera. The report says, as expected, that the new phones will have the A8 processor. This latest report even goes so far as to say when we can expect the new phones: in the second or third quarter.
Meanwhile, there continue to be rumors that the iPhone 5c hasn't sold very well, and that it might be discontinued when Apple introduces the next iPhones. That might mean they'd keep the 5s as their low-end model. They certainly wouldn't offer more than three devices, and it's doubtful they'd keep the 5c on the low end, given that it hasn't sold.
I'm guessing we'll see the iPhone 6 in September, which would be on the same schedule as Apple's more recent iPhone launches, and then we'll see the even larger iPhone at a later date.