Exactly my thought. I still have no good sense for whether or not Apple wants to sell this phone everywhere or just in emerging markets.
The answer to that question will greatly influence what the phone is like, and I really don't know what they're aiming for.
If they sell in emerging markets and skip the US, that could work well for the brand (though some people might be angry.) Though, if they sell it here, they really shouldn't sell something obselete.
Think of the Android phone manufacturer ZTE. Despite the fact they're getting the Nvidia Tegra 4 first, I still think of them as making crappy phones because of the amount of budget phones they sell with lackluster 2-3 year old hardware. I wouldn't want that to happen to Apple's brand, even to a lesser degree.
Should they sell old hardware in emerging markets, it might not be a big deal, but if they sell it in the US, it could be. Think of car manufacturers. They sell sub-par, cheap cars in 3rd world countries. Especially Toyota from what I've seen. But they don't sell those same cars in more developed countries and it doesn't affect the brand's image. And in these 3rd world countries the brand is still a good one because they see the nicer cars from the US and other 1st world countries.
That being said, I'd say the cheaper iPhone will be one processor behind the regular iPhone - so in this case, the A5 - same as the iPod touch. Meanwhile, the larger iPhone would likely get a smaller version of the A#X chip - probably the same chip the iPad mini w/ retina will receive
If that's the route they're taking, I wouldn't be surprised if they put in an A6 chip as the next iPhone would be an A7.
And I'm guessing you think the iPhone + would have a larger screen? If that's the case, it might not even need the A#X depending on what they make the resolution. If it's comparable to the 1136 x 640 iPhone, then it could just be a A#, if they decide to keep retina and make it something like 1600 x 900 (or just a higher resolution), then I can see an underclocked and smaller A#X