I think the 5S will be a better upgrade than people think (because of course, if the numbers on a spec sheet don't go up, its a fail update

....).
I also think the key feature focus (aside from iOS 7 and the fingerprint sensor) will be BATTERY LIFE.
All the rumors point to a relatively small 30% power boost in the new SoC, but Apple is also adding a 8.5% increase in battery capacity. These two things, coupled with new software features that help mitigate battery efficiency and the possibility of IGZO could mean we see a sizable increase in battery life.
Take this year's MBA as an example. Relatively low power boost, but a HUGE gain in battery life. Perhaps Apple thinks the iPhone 5 has plenty of power and has now turned to maximizing battery efficiency?
My guesses - only a day left to wait and see now. Being disappointed before the announcement even happens is ludicrous.