My wishlist. Throwing in everything and the kitchen sink.
Keychain Access
Better Safari iCloud features (forms sync, keychain sync, history sync, etc)
Omnibar for iOS Safari, jesus christ it's about time
Widgets of some sort, yes
Native/App Store VNC/ScreenSharing client app by Apple
Tighter local (bluetooth and/or wifi) sync between devices. Answer phone call on Mac, iPad if you must. Same for text messages. Any text message, not only iMessages.
Let me attach files starting from the mail client dammit. And not only pictures. Holy hell.
Smart keyboard detection.
Setting default apps.
More shortcuts on the home screen. Contacts and other shit.
1 or 2 customizable shortcuts on the lock screen besides the camera. Flashlight comes to mind.
Siri has so much to improve, down to recognition of stuff. It's just very dumb as off now. Let it be able to learn. Yes, Siri, you know that album I'm always listening to. Don't become Voice Control 2.0.
Lazors.
Deeper integration of 3rd party stuff. Open your APIs more Apple.
I'm sure I'll remember more stuff. Apple will probably address one or two of these if we're lucky.