Is this:
Button.Click -= new EventHandler(Button_Click);
the same as this:
Button.Click -= Button_Click;
It is the same. The second is merely syntactic sugar for the first, and equality comparison is overloaded appropriately for delegate types:
Two delegates of the same type with the same targets, methods, and invocation lists are considered equal.
Source: MSDN, Delegate.Equality Operator
The end result is the same. The compiler is inferring the type of delegate automatically and as a result the new operator is not required to create it.