Advantages VB.NET :-
1. Has support for optional parameters which makes COM interoperability much easy.
2. With Option Strict off late binding is supported.Legacy VB functionalities can be used by using Microsoft.VisualBasic namespace.
3. Has the WITH construct which is not in C#.
Advantages of C#
1. XML documentation is generated from source code but this is now been incorporated in Whidbey.
2. Operator overloading which is not in current VB.NET but is been introduced in Whidbey.
3. The using statement, which makes unmanaged resource disposal simple.