I am super proud to announce the first version of the JayData library to support the OData V4 format – and a growing number of V4 features. You can check it out at http://odata-v4.azurewebsites.net/ to see it in action.
A downloadable copy is available at http://codeplex.com/jaydata
JaySvcUtil has also been updated to support the V4 metadata format, grab it from http://codeplex.com/jaysvcutil