OData's $metadata is based on EDM/CSDL, but with Entity Framework 7, EDMX is going away, replaced with code-first (or whatever they decide to call it).
This makes me wonder about using $metadata and the related CSDL spec, which might be at a dead end now. Do you have the same concerns or should I go head first into OData and enjoy its [maybe] short lived support from Microsoft.
OData v4 has just been published as a new OASIS standard, they're not going to drop support for it anytime soon.
The OData team have said that they have not even started working on K-Runtime version yet, I cant find the quote, but basically they mentioned that both the MVC6 and EF7 projects were evolving so rapidly that they were going to wait until things were stablized before implementing it, So it may be some time yet.
