ASP.NET Dynamic Data, ADO.NET Entity Framework, and ADO.NET Data Services were released today as part of the release of the .NET Framework 3.5 SP1. You can also download Visual Studio 2008 SP1. Visual Studio 2008 SP1 comes with the .NET Framework 3.5 SP1.
Download the .NET 3.5 Framework SP1 here and download both Visual Studio 2008 SP1 which includes the .NET 3.5 Framework SP1 here.