iOS 18.3 and MacOS 15.3
Apple released the Beta versions of iOS 18.3 and MacOS 15.3 with additional Apple Intelligence features.
Genmoji for Mac
Genmoji is an Apple Intelligence feature that can be used to generate custom emojis using photographs and textual prompts. MacOS 15.3 adds Genmoji support.
Image Playground in Apple Applications
It is now possible to use Image Playground in Apple’s office applications, Numbers, Pages and Keynote, using newly introduced menu items.
Producing Images with DALL-E within Messages (and other apps)
If ChatGPT is configured to be used with Siri, then you can use DALL-E to generate images while you are in a message and typing into the input area. You can invoke Siri and start your query with ChatGPT (to enforce the use of ChatGPT) and ask to create an image. Siri will pass the request to ChatGPT and that in turn will use DALL-E to generate the image in your prompt.
You can basically do the same in other applications as well, wherever you are in an input field. I tried to use it with WhatsApp, which worked properly. As usual the result depends on the quality and detail of the prompt.

iOS 18.4 and MacOS 15.4
Apple released Beta versions of iOS 18.4 and MacOS 15.4 late February with additional Apple Intelligence features covered in this post.
Categorisation in Apple Mail
This was already available for iOS since iOS 18.2 for the iPhone but now can be used in iPadOS and MacOS as well.
Priority Notifications
It is possible to set an option to allow Apple Intelligence to prioritise notifications.
“Sketch” style in Image Playground
Image Playground can now use the Sketch style in addition to Animation and Illustration styles.
New Languages
This new version of the OS supports Apple Intelligence in several new languages in addition to U.S. English and U.K. English previously allowed.