Because v4 is almost here!
Since yesterday, the ASP.NET Web stack nightly feed contains the packages supporting OData v4. The package is called Microsoft.AspNet.OData and has a working version 5.2.0 – so I’m guessing this is intended to ship with Web API 2.
It relies on the latest beta of Microsoft.OData.Core. OData v4 is a massive changed compared to v3 – you can read about all of them here.