
According to Mark Gurman, iOS 18 is expected to bring significant changes and new features to the iPhone. The main themes and enhancements include:
Artificial Intelligence Capabilities: iOS 18 is anticipated to incorporate generative AI features, which could improve how both Siri and the Messages app can field questions and auto-complete sentences.
Overhaul of Native Apps: iOS 18 is set to update core apps, including Notes, Apple Maps, Calendar, Reminders, and more4.
Control Center Updates: The iPhone Control Center is expected to be revamped, including updates to the 'now playing' music widget and HomeKit smart home controls.
Settings App Revamp: The Settings app is expected to get a cleaner interface, better organization, and improved search functionality.
New Hearing Aid Mode for AirPods: iOS 18 is expected to include a new hearing aid mode for AirPods, enhancing the capabilities of the AirPods Pro 2 and potentially turning them into a significant accessibility device5.
Enhanced Accessibility Features: iOS 18 is rumored to introduce new accessibility features like Eye Tracking, which would allow users to navigate their devices entirely with their eye movements, and Music Haptics, which would translate music into tactile feedback for users who are deaf or hard of hearing.
These are just a few of the expected themes and enhancements. The official announcement of iOS 18 at Apple's Worldwide Developers Conference will provide more details on the update's features and improvements.

The revamp of the Control Center in iOS 18 is considered overdue because the current design has not changed significantly since the launch of the iPhone X back in 2017. In the world of technology, where updates and improvements are frequent, a period of six years without a major overhaul can make a feature feel outdated or in need of a refresh. Additionally, users have expressed frustration with certain aspects of the Control Center, such as the layout of HomeKit accessories and the size of the 'now playing' music widget. These factors contribute to the perception that an update to the Control Center is overdue.

The iPhone Control Center is expected to undergo some updates with the iOS 18 update. While specific details about the changes have not been revealed, it is anticipated that there will be updates to the 'now playing' music widget and the HomeKit smart home controls. The Settings app is also getting revamped with a cleaner interface, better organization, and much-improved search.
Currently, in the Control Center, audio controls are displayed in a small 2x2 square platter in the top-right of the screen. Users have requested to make the Now Playing UI much bigger, perhaps to include album art and a progress bar by default. In iOS 17, users have to long-press and wait to reveal those additional elements.
Regarding HomeKit, the iOS system currently selects up to six accessories to display in the Home section of the Control Center. Users can click on the double-width Home tile to reveal a mini-version of the Home app, with their favorite accessories organized by the room they are in. However, the automatic layout is often not what the user wants, and the layout can change seemingly at random, making it difficult to learn muscle memory for common controls.
It is expected that users will be able to manually choose which accessories to include in the Control Center and have a fixed layout of what they want always visible. Making these tiles larger—like they are in the Home app itself—would also improve ease of use. In this particular case, users would welcome less 'AI' and more manual control for the iOS 18 update.