// *** before: ***
// there was no supported way back from an interface reference to the
// object behind it, so the interface carried an extra method for it
type
  IPerson = interface
    ['{9E8C4A20-1F2E-4C7A-9B41-7B6F2D5A18C3}']
    function GetSelf: TObject;
    function GetName: string;
  end;

var
  Intf: IPerson;
  Obj: TObject;
begin
  Obj := Intf.GetSelf;      // every interface needed its own hatch
end;

// *** in version 2010: ***
type
  IPerson = interface
    ['{9E8C4A20-1F2E-4C7A-9B41-7B6F2D5A18C3}']
    function GetName: string;
  end;

var
  Intf: IPerson;
  Obj: TObject;
begin
  Obj := Intf as TObject;   // the compiler and the RTL do it for you
  if Obj is TPerson then
    Writeln(TPerson(Obj).ClassName);

  // careful: the object is still owned by the reference count of the
  // interface, so do not free what you got this way
end;