ORTC and WebRTC are separate groups in the W3C. You can think of the ORTC "Community Group" doing more exploratory work on a future version of the API while the WebRTC "Working Group" is finishing the 1.0 version. The work the ORTC Community Group is doing may or may not be adopted by the WebRTC working group as a future version someday, or maybe it will adopt some parts but not all.

The currently drafted ORTC API still allows all of the power to the Javascript apps to interoperate with "legacy stuff", but it also allows the JS to bypass most of it.

(I'm a member of both the WebRTC Working Group and the ORTC Community Group)