Creating an IComponentRegistration using the Registration class is a vastly 
different experience to that of registering a component using 
ContainerBuilder.

Proposal is that a series of helper classes are created:

var instance = "Hello!";
var registration = new InstanceRegistrationBuilder<string>(instance)
                 .As<object>()
                 .Named("foo")
                 .Build();

Careful crafting of these types will let them power ContainerBuilder and 
enable cleanup of the Registrar types (which really need to go.)

Additional goals should be to carry type information through the fluent 
interface.

This is particularly relevant to dynamic registration sources. E.g. anyone 
implementing IRegistrationSource needs to be able to create registrations 
simply and on-the-fly.