IIRC, LINQ can be translated to C# 3.0 without LINQ, so I guess it is syntactic suger but for C# 3.0. To implement it in C# 2.0 one would need to replace expression trees with “home made” query specification classes. It would be a lot of work, it would not be standardized, and it would not be integrated in the language.
So the real new feature in C# 3.0 are the expression trees. LINQ is only one place where expression trees are used.
So the real new feature in C# 3.0 are the expression trees. LINQ is only one place where expression trees are used.