As said in summary, is not possible to add generifyied component to/from
pallete, because can't define data type in declaration/constructor.

Suppose following JComboBox replacement:

public <T> class MyComboBox<T> extends JComboBox {
  public MyComboBox() {
    super();
  }

  public T getSelectedItem() {...}
  public setSelectedItem(T selection) {...}
}

So, since there is a lot of effot to incentive people to use generics (the 1.3
to 5.0 migration guides and so on), I think IDE should completelly support
generics (not only in code editor, but Form editor too).