Case manufacturers use mockups in order to make cases and have them ready when new iPhones become available. Those mockups are dummy iPhones based on the specs of the actual device. Which means they can give a sense for what the new iPhones will look like. According to AppleInsider, over the weekend, Sonny Dickson, who has in the past been the first to post leaked photos of new iOS devices, posted to Twitter photos of mockups for the expected 4.7-inch and 5.5-inch iPhones. This is yet one more bit of evidence that larger phones are coming, with the 4.7-inch iPhone 6 expected to be announced in September. The mockups show styling continuity with the iPad Air and iPad mini, with the same sort of rounded edges. The similar shape of the two mockups suggests that the new larger phones will share the same aspect ratio—which would be expected from Apple, as they typically try to make it easy for developers to port their apps to differently sized models.
Of course, the design could change before the next iPhone is released, so it's prudent not to put too much stock in the details. But it does seem virtually certain that we'll be getting two larger iPhones this fall.
And it seems increasingly likely that we'll be getting an iWatch or other wearable in October. On Sunday the New York Times ran an article about Apple under Tim Cook and discussed whether he's as closely involved in development of new devices as the late Steve Jobs. The article cited lower-level employees who said that Cook isn't as involved in the smart watch as Steve Jobs likely would have been, instead delegating oversight to famed Jony Ive and other executives. The unnamed employees who spoke to the NY Times said Apple's smart watch is expected in the fourth quarter of this year. Interestingly, the article says that rather than being focused on the details of the smart watch hardware, Cook is more focused on its broader implications for health and fitness monitoring. I think that's smart, and that the success of Apple's smart watch will hinge on the larger ecosystem it integrates into.
The original iPhone was closed to developers. The gadget itself was the focus. But Apple eventually opened it up to developers, and the ecosystem and integration with the cloud has become an important feature of the device. So Apple has done well to create the ecosystem first, with HealthKit, and then will launch the device once this fledgling ecosystem is starting to grow.