Here are my guesses.
- iPhone will debut on another carrier in the US sometime in within the next 12 months. Maybe Verizon, Maybe T-Mobile, but another carrier none the less. But this is just a guess.
- The next iPhone most likely wont be LTE unless LTE expands rapidly. Apple isn't known for jumping into the newest technology without it being ready to be used well. I don't see LTE being ready by next year. But then again, this is just a guess.