Touchscreen on the back of the phone with special gestures, 64gb, Apple A5(?) processor based on the dual-core Arm Cortex A9 processors, 8mp camera, slightly improved battery life, HD video out, possible RFID support that would also include wireless payment options for their new iPay service, based on the 150+ million iTunes accounts that are already linked to credit card data.
As for iOS 5, we will likely see an overhaul to the appearance of the UI. The iPhone interface is growing stale. The light blue pinstripes need to go! I'd also expect better file management and connectivity with the cloud, along with faster code execution via the new xCode 4, which according to AppleInsider, allows iOS code to run up to 60% faster with better memory management, which should mean better applications that crash less often. We will also likely see a more streamlined notification interface. Maybe also dynamically updated application icons, like the calendar now, but for other icons like weather, with an API for developers to use backgrounding to change them on the fly to present useful information to the user. Lastly, I would expect some sort of dashboard like implementation. Maybe a landing screen, maybe able to be activated on the lock screen, maybe that is also a part of the new notification system. It would allow users to view all their latest information, including news feeds, mail, texts, weather, calendar for the day, and to-dos all in a convenient location. They might also bring some of that location based icon stuff from the patents in.