After trying out the new features of Orcas Beta 2, I noticed using LINQ to SQL projects, designers don't support SQL Server Compact Edition. The only way is using sqlmetal.exe command tool that allows to create either code, map, desginer files from any SQL Server database (any edition). I don't like this kind of tools, are so slow, so I decided to create a project to use sqlmetal.exe more easily under user graphic interface with .NET 3.5. My first idea was to create a Visual Studio AddIn but I didn't know how to begin besides was to busy to spent some time learning.
I created an User Control project using C# and embedded it into a Windows Forms project. Now I have my own SQL Server Compact Edition 3.5 database's generator to use with LINQtoSQL projects and is so usefull.
I think that it could be usefull for others developers and I just upload it in http://www.codeplex.com/ called SqlMetal Open Source User Interface (sqlmetal osui). You may download the source and test it and if you want, participate in the project.