C# 4.0 has a lot of new major features such as dynamic type, covariance and contravariance, named arguments etc. But C# 4.0 contains new minor (but useful) changes such as TryParse method for TimeSpan, Enum, Guid data types, String.IsNullOrWhiteSpace, System.IO.Stream.CopyTo etc. What other minor and useful features of C# 4.0 can you list?