We received a few questions asking if CTP1 of ADO.NET Data Services v1.5 includes a Silverlight library. The short answer is yes, we included a Silverlight library initially intended for use with Silverlight 2. Once you install v1.5 of data services, you can find the SL library in the "Program Files\ADO.NET Data Services V1.5 CTP1\sl_bin" directory. The Silverlight library is a superset of what we shipped in the Silverlight 2 SDK and includes all the same enhancements we have made to the .NET Fx-based client library shipped with v1.5 CTP1.
As a heads up, we have a known bug in ADO.NET Data Services v1.5 CTP1 when using the "Add Service Reference" Visual Studio gesture. Basically instead of setting the assembly reference to the data services client library as CopyLocal=true, the Add Service Ref sets it to false. If you have hit this issue, check out Phani's blog post here for a detailed description of the simple workaround.
Also, if you are using Silverlight 3 and want to give ADO.NET Data Services 1.5 CTP1 a spin, check out this post for instructions.
ADO.NET Data Services, Program Manager