An Apple Store at night.

Image source: Apple.

Apple's (AAPL 0.33%) upcoming iPhone 8 is one of the most hotly anticipated gadgets of the year. Thanks to the Apple rumor mill, we already know a lot about the features that might be included -- a glass body, a faster A11 processor, wireless charging, and a Touch ID sensor and a forward camera that are both integrated into an edge-to-edge OLED display.

However, we've spent less time talking about the features that we probably won't see in the iPhone 8. Let's take a closer look at eight things that will likely be missing from Apple's tenth anniversary device.

A man holds a lot of SD and Micro SD cards in his hands.

Image source: Getty Images.

1. MicroSD card slots

Apple has never added MicroSD card slots to iPhones, because it allows the company to charge higher prices for higher-storage iPhones. Current rumors suggest that the highest-capacity iPhone 8 will have 256GB of storage.

However, Samsung's (NASDAQOTH: SSNLF) lineup of Galaxy S8 devices includes MicroSD slots which support cards with up to 2TB of storage -- even though the current limit is 256GB.

A SIM card placed next to a smartphone.

A SIM card placed next to a smartphone. Image source: Getty Images.

2. Dual SIM cards

Dual SIM devices are popular in high-growth mobile markets like China and India, because they let users mix and match cheaper voice and data plans, as well as keep separate work and home numbers on a single device.

Early rumors suggested that Apple would add dual SIMs to the iPhone 8, but recent reports indicate that it will only feature a single SIM slot. The main reason is that the major carriers that promote flagship devices like the iPhone 8 and Galaxy S8 prefer locking in users with single voice and data plans -- which boosts their profit margins.

Energous' WattUp wirelessly charges devices via transmitters.

Energous' WattUp wirelessly charges devices via transmitters. Image source: Energous.

3. Long-distance wireless charging

Apple reportedly struck a deal with Energous (WATT -4.35%), a pioneer in long-distance wireless charging, last December. Since Energous' WattUp charging tech can charge devices from 15 feet away, it was widely believed that the iPhone 8 could be charged without a cable or a wireless charging pad. The Qi wireless charging standard used by Samsung's Galaxy S7 and S8 only charges devices from 1.6 inches away.

However, Copperfield Research recently suggested that Apple didn't plan to add long-distance charging to the iPhone 8. Instead, it suggested that the deal with Energous was instead aimed at keeping the technology out of its rivals' hands.

Xiaomi's Mi Mix.

Xiaomi's Mi Mix. Image source: Xiaomi.

4. The Home button

Apple will reportedly replace the Home/Touch ID button from the iPhone 8 with a "function area" that reads fingerprints directly from the display. The need for a Home button will likely be solved via software changes in iOS 11.

That's because the iPhone 8's entire screen is expected to be an edge-to-edge bezel-less display similar to Xiaomi's Mi Mix. The first generation Mi Mix placed the fingerprint sensor on the back, but the second-generation device will reportedly also put the fingerprint sensor on the display.

A picture of Samsung's Galaxy S8 that highlights its curved edges and bezel-less display.

Samsung's Galaxy S8. Image source: Samsung.

5. A curved OLED display

Samsung sparked an aesthetic shift when it launched the Galaxy Note Edge in 2014. The display's single curved edge was evolved into two curved edges with the Galaxy S6 Edge, and has since become the defining feature of its high-end Edge devices.

Early rumors indicated that Apple would finally add a curved OLED screen to the iPhone 8, but numerous analysts -- including KGI Securities' Ming Chi-Kuo -- claim that Apple scrapped that plan.

A man uses the Galaxy S8's iris scanner.

The iris scanner on Samsung's Galaxy S8. Image source: Samsung.

6. Iris scanner

Samsung's Galaxy Note 7 will likely always be remembered as the "exploding" phone, but it was also the first Galaxy device to use an iris scanner to unlock the device. Samsung has also added the feature to its S8 and S8+ devices. The iPhone 8, however, isn't expected to add this futuristic feature.

Samsung's DeX Android desktop.

Samsung's DeX Android desktop. Image source: Samsung.

7. Desktop mode

The Galaxy S8 also features a "desktop mode" which converts the device into a desktop computer -- powered by Samsung's DeX window-based Android desktop -- when hooked up to a monitor. The idea is similar to Microsoft's (MSFT -2.53%) Continuum, but that effort hasn't gained much steam due to weak sales of Windows 10 Mobile devices.

Apple, which is often criticized for not merging iOS and OS X into a single OS, won't add a desktop feature to the iPhone 8. Doing so could cannibalize sales of Macs and upset the balance between the two operating systems.

A man listens to music on his smartphone with wired headphones.

Image source: Getty Images.

8. A 3.5 mm headphone jack

Apple's most controversial design move with the iPhone 7 was the removal of the headphone jack. Critics complained about the need to charge Bluetooth headphones, their poorer sound quality when compared to wired headphones, and the use of clumsy lightning adapters to use regular headphones.

Samsung not only kept the headphone jack in the Galaxy S8, but it doubled down on wired headphones by bundling a pair of $99 Harman AKG headphones with the device. Apple, which rarely backtracks on its design choices, won't likely bring the jack back in the iPhone 8.