I just read a fantastic quote about LINQ from the book Pro LINQ: Language Integrated Query in C# 2008 by Joseph C. Rattz, Jr.:

I prefer to think of LINQ as a data iteration engine, but perhaps Microsoft didn’t want a technology named DIE.

I think they already built the technology for such a product, and put it in Vista. :)

It’s a great book. The first LINQ book I’ve found with a really detailed explanation of LINQ-to-SQL and the SQLMetal generation tool.