iPhone 5 is NEW.
- Bigger screen; increasing the resolution to 1024x768 to keep it "Retina" with a bigger screen, existing apps running in an inner section.
- Global phone for all networks (AT&T, Verizon, etc)
- Shaped more like the newest iPad & iPod touch, curves on the back like those.
- 8MB camera is one thing I'd be 100% about.
- NOT increasing the memory choices, still 16 or 32GB.
iPhone 4S is newish. It will replace the 3GS and 4 as the low end model.
- Some updated things from the iPhone 4, mainly to be a global phone that works on all networks (AT&T, Verizon, etc.)
- The same camera.
- The screen from the iPod touch to save some costs. (They're both retina & the same resolution, but the iPod touch's screen is a bit different on the inside. From straight ahead they look identical, but at an angle the iPhone's does better. The iPod's is presumably cheaper.)
- 8GB as the only choice.
- Maybe a bit thinner, but looking pretty much like the iPhone 4.
- All that and it will be cheap. $0 with a contract, and close to the iPod touch price without: $299.