There is one thing I am waiting for, and one thing I want to speculate about: it is the AI Kit for iOS.
For some time Apple is using neural network (and some others crazy machine learning techniques with focus on low energy footprint) for face recognition. For me - it is only a small portion of what they’re cooking inside, and if i was ever waiting for anything to be shown on WWDC - AIKit is the definitely something I am dreaming of.
Try to imagine, it is a new way of collecting and manipulating data, it would be also great for making apps more context-oriented, providing users with informations that they really care about, without forcing user to provide app with data and to customise output/notifications/screens/whatever.
I’m waiting for context, location and time aware notifications for oh so many years. And I believe with something like AIKit (locally stored informations, not shared, encrypted, safe) we could finally achieve it.