http://msdn.microsoft.com/netframework/future/linq/
http://channel9.msdn.com/showpost.aspx?postid=114680
http://blogs.msdn.com/danielfe/archive/2005/09/13/464904.aspx

I think this is not a promising approach. Treating whole data in the same way looks plausible, but it can not succeed.

A simple collection in .NET CLR and a table in a SQLServer are entirely different from each other. Let me give you some examples: 1) tables are stored in disk, while collections are stored in the main memory, 2) collections are usually in the same machine where programs run, whereas tables are stored in the database server, and 3) iterating collection items is cheap, whilst set operation is more cheap than iteration in case of the database applications.

Anyway, this project is interesting.