This happens because Microsoft decided to change names again:
"To support side-by-side deployment with existing .NET Framework assemblies, the assemblies in this release have been renamed from System.Data.Services to Microsoft.Data.Services. The actual WCF Data Services namespaces are unchanged."
We cannot build our assemblies against two different sets of Microsoft assemblies.
We have plans to reference the new assemblies starting with Microsoft only for our WPF 4.5 version. The old versions (.NET 3.5 and 4.0) will continue to reference the "standard" WCF Data Services assemblies starting with System.
Do you want me to send you some un-official .NET 4.5 binaries built on my machine referencing the new Microsoft-starting WCF Data Services assemblies? You can use them for testing purposes only.
the Telerik team