Supply chain chatter suggests Apple considering two OLED, two LCD iPhone models for fall 2...
A new report from the Chinese supply chain suggests that Apple is continuing to evaluate multiple sizes for the fall 2018 releases, with the latest claim saying that the the company is evaluating a 5.7-inch and 6-inch LCD device, plus both a 6-inch and 6.4-inch OLED iPhone.

The data gleaned on Friday from the supply chain by DigiTimes' research arm claims that Apple is leaning towards the two LCD devices, and a large-format 6.4-inch OLED one. It isn't clear where DigiTimes sourced their data, and it lies in contrast to multiple reports from KGI Securities Ming-Chi Kuo.
Also noted in the latest report is support for wireless charging and "3D sensing functionalities" across the entire line. It isn't clear what the venue is talking about with "3D sensing," be it the TrueDepth camera, 3D Touch, or some other technology.
DigiTimes generally has accurate information from individual component manufacturers regarding delivery timetables. However, it has a poor track record on Apple's specific plans -- and the veracity of the data from the newly formed DigiTimes Research division is unknown.
The venue has given itself an out, should the information prove to be inaccurate. It notes that "Apple has not yet made the final decision so there is still a chance that the vendor may come up with another combination."
Other rumors suggest that Apple is looking to produce a 5.8- and 6.5-inch OLED iPhone for the fall of 2018, with a low-cost 6.1-inch LCD model eschewing the dual-lens camera in the iPhone 8 Plus and iPhone X.

KGI Research predictions for the fall of 2018

The data gleaned on Friday from the supply chain by DigiTimes' research arm claims that Apple is leaning towards the two LCD devices, and a large-format 6.4-inch OLED one. It isn't clear where DigiTimes sourced their data, and it lies in contrast to multiple reports from KGI Securities Ming-Chi Kuo.
Also noted in the latest report is support for wireless charging and "3D sensing functionalities" across the entire line. It isn't clear what the venue is talking about with "3D sensing," be it the TrueDepth camera, 3D Touch, or some other technology.
DigiTimes generally has accurate information from individual component manufacturers regarding delivery timetables. However, it has a poor track record on Apple's specific plans -- and the veracity of the data from the newly formed DigiTimes Research division is unknown.
The venue has given itself an out, should the information prove to be inaccurate. It notes that "Apple has not yet made the final decision so there is still a chance that the vendor may come up with another combination."
Other rumors suggest that Apple is looking to produce a 5.8- and 6.5-inch OLED iPhone for the fall of 2018, with a low-cost 6.1-inch LCD model eschewing the dual-lens camera in the iPhone 8 Plus and iPhone X.

KGI Research predictions for the fall of 2018
Comments
The iPhone 8 looks a little dated to me, not being edge to edge. So it makes sense to me. Two sizes of X's with OLED and two sizes of iPhone 9's with everything but the OLED screen.
Apple always does a good job of tightening up their product line...eventually. (Look at the iPad offerings. Very strong.) And they do a good job in the products getting the latest feature sets. Again, eventually.
Seems simple enough.
Best.
P.S. Doubt they will call it the Xs ('excess')
Jony wants two pieces of black glass 'glued' together with no ports and no buttons, no screws. The future.
I expect that such new iPhone models are all likely to deploy hardware-patched (updated versions of existing) A CPUs or variations of a brand new A12 CPU to cater for the 3 most serious security issues that impacted Apple since last summer, hard to be resolved by software-only patches:
I also expect that the recently released Home Pod is already deploying a hardware-patched A CPU catering for the same safety issues (it could be the reason for its delay).
Apple had enough time since summer 2017 to work on such hardware patches, and with a radical CPUs upgrade of this kind it will finally be equipped to mitigate further litigation in 2018 while sending a refreshed security/privacy marketing message.
That's a good point. Just to expand on dinoone's prediction, I think we see the following line-up
Edit:
$999 - iPhone X 6.5"
$899 - iPhone X 5.8" (updated)
$749 - iPhone 9 6.1" (LCD / FaceID)
$649 - iPhone 8 Plus 5.5"
$549 - iPhone 8 4.7"
$449 - iPhone 7 4.7"
$349 - iPhone SE 2
1. 6.5" iPhone X+ at $999
2. Current iPhone X at $849 (no refresh)
3. New LCD iPhone (9) in new iPhone X form factor at $749-$799.
4. iPhone SE2 in new form factor at $399-$499?
If they were to create a new screen size for the future models with the Face ID sensor, I think to make sure that you can fill the screen outside of the notch with 16:9 content would be a winner for the video experience on future notch iPhones. The current iPhone X widescreen is definitely not designed with 16:9 content in mind. I really like the overall format of the X, but I don't like either cropped or side boxed video.