It'll likely be some time after 1.0.
We are currently working on the more fundamental pieces that handle transitioning content in the same container, which is a pre-requisite for shared-element. As much as we'd like to provide these features ASAP, we prefer not to rush the feature design as that would cause more churns and frustrations down the line. 🙂 In the meantime, there's a number of open-source solutions available right now. (You could search in this channel to check them out.)