"OPC UA is now available on the open-source repository of GitHub. Open sourcing OPC UA technology allows groups such as academia and research organizations, as well as many suppliers and end-users, to assess and make potential enhancements to the code. The OPC Foundation will continue to maintain the integrity of the OPC specifications by requiring reference implementations prior to releasing any OPC specifications or enhancements that might arise from this initiative."
Whether OPC UA solutions parlay into mainstream Industrie 4.0 is a worthy question. At this point in time Industrie 4.0 is diverse with user stories and alternative protocols. Going open source could help make the case for OPC UA, especially where the application scenario calls for a rich feature set. On the other hand, use cases for device sending data to a cloud service might benefit from a lightweight approach.