We've updated the sample provider to work with Beta 1 of Orcas.  The sample provider is available for download as an attachment to this blog post.

Within the Entity Framework, the command tree, expression and related classes in Beta 1 now include the "Db" prefix - DbCommandTree instead of CommandTree, DbExpression instead of Expression, etc.  The primary change to the sample provider itself from the March CTP is to react to those modified class names.

The solution that contains the sample provider also includes a modified version of the 101 LINQ to Entities samples project.  The modified project uses the sample provider rather than System.Data.SqlClient.

As with the March CTP build, the sample provider wraps System.Data.SqlClient and demonstrating the functionality a provider needs to add in order to support the Entity Framework.  To learn more about the classes and interfaces to implement, see the blog post for the March CTP version of the sample provider here.

If you're writing an ADO.NET provider for Orcas and you're not already in touch with me, please drop me a line at David (dot) Sceppa (at) microsoft (dot) com.  Enjoy!