LINQ to SQL之上的面向对象模型

I'm playing a bit with LINQ to SQL and overall it's a much better option than what Microsoft had before (DataSet), but it seems that object-oriented capabilities are still limited. Since we currently use a custom persistence framework that created a OO model on top of DataSet, I'm looking to port the framework to a new version building a OO Model on top of LINQ to SQL.I'm playing a bit with LINQ to SQL and overall