Besides the new 13MP camera, we should see a new Apple A7 processor under the hood, an improved battery, and the long-rumored fingerprint scanner. The latter is the rumor that just won't die. The screen is expected to remain at the 4 inches introduced by the Apple iPhone 5 with the same materials and design with perhaps a little thinner footprint. Of course, iOS 7 will be installed out of the box.
When the Apple iPhone 5S arrives late in Q3 or early in Q4, it could have a side kick in the low priced Apple iPhone. Aimed at emerging markets where the price of an iPhone makes it hard for consumers to buy, Apple has been trying to decide where to cut corners and where to leave things as is. We could see 8GB of native storage inside a thicker, plastic case and a rear camera less advanced than what will be on the new Apple iPhone 5S.
source: Weibo (SubscriptionReq'd) via SlashGear