I would be against rating decay, but something would be nice to prevent unused names from lingering in the top lists. My idea would be to introduce a "Hall of Valhalla" idea, wherein names that have not been used in rated for a month are moved to Valhalla, and out of the active list. A name can be brought back simply by playing a rated game with it, so it would not be permanently lost. But it would keep the top players list restricted to active players, which is what it should be.
Little_wing
Oh as I was young and easy in the mercy of his means,
Time held me green and dying
Though I sang in my chains like the sea.