The entry and listbox widgets gained new options for controlling their state:

The entry widget state attribute now supports a readonly value. When an entry is in the readonly state, the value displayed cannot be changed by either the application or the user, and the insertion cursor is never displayed. However, the user can still select the contents of the widget. The entry widget also supports new disabledForeground, disabledBackground, and readonlyBackground attributes to control its appearance in the different states.
The listbox widget now supports a state attribute, with normal and disabled states, and a disabledForeground attribute to control its appearance in the disabled state. Additionally, a new activeStyle attribute controls the style in which the active element is drawn. (TIP #94)