Explain current thinking around IClonable.

Many developers feel that, as there's no generic version and few methods take an ICloneable parameter anyway, ICloneable is not worth implementing. As the Clone() method returns an object, you always have to cast it to its actual type before you can do anything with it.

Another problem is that it's not clear from the name whether you're implementing a shallow or a deep clone.

This doesn't of course mean that you shouldn't write clone methods for your classes - just that there's no compelling reason for them to have the same signature as the ICloneable.Clone() method.