I'm not expecting any changes, I'd imagine they'd keep the same screen and processor, so I have no clue how they could possibly market it..... Especially after how much of a disappointment the iPhone 5 was. Sure, they can throw an NFC chip in there, but they should have done that already..... If they think another slight improvement will help them, it'll just make us more disappointed and destroy they're reputation.
Right when the iPhone 5 came out, I was, and still am 100% confident they'll release an iPhone 5S (or similar name) 6-12 months after the release of the iPhone 5. I was going to buy the 5, but I'm happy with my 4, and decided to wait to see if he 5S would be worth it. If not, I'm probably switching to an Android or Windows phone.
I saw these pictures a few days ago, and I'm not surprised a few pictures got leaked (if they're legit). A lot of iPhone 5 got leaked. These aren't worth getting worked up on though, they just make us hope that Apple can show us something new without the help of Steve Jobs. I'm not expecting anything big though.