Hi,
The ArcGIS Runtime SDKs (WPF, WP, Java, Android, iOS, etc) all have new, native APIs and new architectures which are designed to take advantage of asynchronous programming patterns and modern multi-core computing platforms. These APIs will not necessarily have any direct correlation to ArcObjects. Therefore migrating from an ArcObjects-based solution to a solution based on, for example, the ArcGIS Runtime SDK for WPF will mean you need to redesign and rewrite.
But talk of converting between the two and deep copying sounds like you're considering a hybrid solution?
Cheers
Mike