we are planning to contribute the non-AEM specific parts to the Apache Sling project - see SLING-5886.
the AEM specific parts remain in wcm.io and will be the basis for the next major version 2.0 of wcm.io Configuration. additionally the configuration support will be refactored and enhanced in serveral areas. a compat bundle will be required to help existing wcm.io-based Projects migrating to this new version.
the roadmap of the configuration features to be supported is outlined in this wiki page (column "Conf V2"):
the features in detail and their support is still subject to change.
another goal is to be able to integrate with the already existing configuration mechanisms in AEM (see https://wcm-io.atlassian.net/wiki/x/BwBLAQ for an overview). we will see how far we can get with this.