There has been an unprecedented amount of leakage concerning Apple’s iPhone 6, due to be released in 3 or so months. It seems all but certain that there will be two versions, both bigger than the current size, with 4.7“ and 5.5” screens. We know the phone will have more rounded edges, and will be around 6.7mm thick.

So what do we not know?

Premium Features

It has been rumored that there may be more than just a difference in screen sizes between the 4.7“ and 5.5” models. You might have to pay extra to get some of the fancy features this time, similar to what happened with the iPhone 5s compared to the 5c:

Sapphire Screen: Apple’s new sapphire glass technology, being produced in large quantity at their new plant, has long been rumored as a replacement for the surprisingly fragile Gorilla glass. (A key difference is scratch resistance, as a scratched screen is much likelier to break.) It is currently used only for the Touch ID sensor in the iPhone 5s home button. Apple has been ramping up production, and it looks like it is setting up to produce much more sapphire than could be used in an iWatch only. However, you may be only able to get it in the 5.5“ model, if certain rumors are to be believed. Not everyone is saying so; competing rumors hold that there will be enough sapphire to go around, allowing for both iPhones and the rumored iWatch to get the goodies.

Optical Image Stabilization: This should be coming also, but again, maybe only to the 5.5” model. Presumably this would allow users to take movies with a lot less hand-held jitter.

Standard Features

Several more features have been rumored, but nothing is set in stone. What should be included, from most likely to least:

Apple’s New A8 Chip: Apple has been designing its own mobile CPUs for a while now, and these chips have very good performance, at least since the A6, with the A7 showing very good numbers. The A8 will hopefully deliver even more power and speed. Th A8 may deliver better power consumption as well, so you should expect slightly improved battery life—unless the bigger screens take a bite out of that.

Better Camera: which might not mean a higher resolution camera. The built-in back-face camera might still have “only” 8 megapixels. However, the autofocus might be faster and better, and the camera app might have more features—the apparent time-lapse feature to match the previously-added slow-motion feature, for example.

NFC Chip: This would be a surprise, because Apple has said that it is not currently on their radar. However, several reports have come out saying that Apple is ready to deploy a mobile payment system, and that the iPhone 6 could be equipped with the ability to tap or swipe your phone over a sensor and then use Touch ID to clear the payment. Presumably, the charge would come out of your iTunes Store credit card account.

While NFC is still relatively underutilized in America, it is pretty widely used in Japan. I know that I would love it if the iPhone 6 could hold my train pass (I currently swipe my wallet), but in all likelihood, train lines will not let Apple carry their monthly passes, instead favoring their own system. The best that I would hope for would be to use the iPhone for straight purchasing of items or individual train fare payments.

Inductive Charging: We’d all like it if this were true, but it’s one of the rumors I’ve heard least about. This would allow you to charge your phone just by placing it on top of a pad. Apple presumably would supply that (at a higher-than-usual cost, natch; these cost from $20 to $25 and up, so expect Apple to start in the $40 to $50 range at least). It would go along with Apple’s new Cloud initiative, updating less through iTunes than from your iCloud account. This would be nice but far from a huge deal, which is why I am doubtful.

Haptic Screens: Haptic screens provide touch feedback by vibrating as your finger runs over the surface. Aside from the battery drain, this just sounds like to much trouble for too little return. It seems like a nice ornament but not much else—and Apple is trying to make these machines smaller, and not add anything instead, especially for a throwaway special effect. But who knows?