"Hey Siri" support and possibly wireless charging case alongside AirPower charging mat.
AirPods and AirPower: Everything We Know
New iOS 8.3 Features: Speaker Calls With Siri, No Password Required to Download Free Apps
With the iOS 8.3 beta 3 installed, users can now ask Siri to make phone calls using the iPhone's speaker. If you ask Siri to "Call [name] on speaker," the call will be made via speakerphone, enhancing Siri's hands-free capabilities. If you make the same request in iOS 8.2, Siri ignores the "on speaker" part and places the call as normal.
The new feature makes it possible to activate Siri while plugged in by saying "Hey Siri" and make a phone call, all without needing to touch the phone or put on a headset for hands-free operation.
In the Settings menu of an iOS device running iOS 8.3 beta 3, there's a new option under iTunes & App Store labeled "Password Settings." In this section, there is an option to change the password settings for purchases and in-app purchases, choosing options to either "Always Require" a password when making a purchase, or to "Require After 15 Minutes."
"Always Require" and "Require After 15 Minutes" are not new settings -- the options have previously been located within the Restrictions section of the Settings app -- but a user is required to select one in order to access a new password toggle setting, which lets users toggle the password requirement for free apps on and off. When toggled on, downloads labeled as "GET" in the App Store will not require a password.
Apple's new Password Settings are not functional right now, returning a "Cannot connect to iTunes Store" message when tapped, but it's likely they will be made available in a later beta ahead of the update's public release. The Password Settings menu can also be found under General --> Restrictions.
In addition to the newly discovered features listed above, iOS 8.3 adds quite a bit of new functionality to Apple's mobile operating system. Earlier betas have introduced a wireless CarPlay feature and several emoji changes, like a new emoji picker, diversified emoji with skin tone modifiers, new flags, and new icons for the watch, phone, and computer emoji, which now resemble an Apple Watch, an iPhone, and an iMac. Most notably, keyboard spacing has been changed to prevent users from hitting the period key when they meant to hit the space key when searching in Safari.
There's also support for Google two-factor authentication when adding Google accounts on iOS, Apple Pay support for China UnionPay, new Siri languages, filtering options for Messages, and more. We've been keeping a complete list of iOS 8.3 changes in our iOS 8 Features Roundup.