Microsoft wants others to get involved in building the next version of the Entity Framework.
The source code is found here:
The Mono Project is working to get the open sourced Entity Framework to work on Mono.
So, with Oracle working on a thin ODP.NET provider, hopefully, it will work on Mono too. But no guarantee from Oracle. I know at first, the thin ODP.NET provider will not support Entity Framework, but down the road it could (hopefully).