Not like old widget extension which used wxWidgets, but custom-made one, similar to controls present in recent Pixi effects demo: viewtopic.php?f=18&t=6322
It would make easier to create UIs for our games, as build-in widgets would take care of such things as checkboxes, radio buttons, buttons, scroll bars, and so on.
Every radio button would have special GroupID setting that would define which radio group it belongs to (essentially which buttons are turned off when you click specific radio button).
Of course graphics of pressed/not pressed/mouse hovered controls would be fully customizable.