While virtual worlds have been around for some time, the persistent, 3-D online versions became especially realistic and popular in the mid-2000s.  Many universities created virtual-world campuses and offered courses on those campuses.  Since roughly 2009, enthusiasm for virtual worlds in education has declined (a la the Gartner Hype Cycle); but increasingly accessible VR technologies and new virtual-world platforms may be leading to a renaissance.  The purpose of this talk is briefly to examine the nature of virtual worlds, focusing on Second Life, to describe how they have been used by educators in the past, and to speculate on what the future may hold.  This presentation is informal, based on twelve years of personal and professional experience.  Discussion is encouraged.