How else are they going to sell the 6S?
I'm guessing that by "else" you mean in addition to the usual laundry list of improvements that Apple adds to its "S" models:
- Faster processor.
- Camera improvements (13 MP? OIS on both models?)
- Sensor improvements.
- Perhaps an all-new feature or two.
The else may quite possibly be:
Apple has never released an "S" model with improvements in just one area. There is no reason to expect them to start now.
Also, I don't recall them ever emphasizing the amount of RAM, even when they've doubled it in the past. That's more of an under the hood enhancement than a marketing point. If it happens, it may be obliquely hinted at in their keynote, but the tech blog junkies will have to read every leak and review post hoping for a mention of the "bigger GBs", while the everyday iPhone user won't really be aware.