Recent reports claim that while wireless charging will be available for the 2017 iPhone models, it won't be available at launch. It might not make its way around until iOS 11.1 is released.
The charging will reportedly be inductive charging, and despite previous claims that the feature will only exist for the more expensive model of the iPhone 8, the latest rumors suggest that the feature will be available on all three models of the phone. It will also be sold separately from the phone. Hopefully we'll have more details soon enough.