Sony says that, to-date, it has managed to "move" 10.5 million units of its Move peripheral for the PlayStation 3. The figure was revealed by Sony developer support engineer Gabe Ahn after a Game Developers Conference panel on developing games for the company's motion sensing controller. That figure represent "units shipped to retailers" and not "units sold." Further, Ahn says that the Move attach rate is one for every six PlayStation consoles sold as of December 31, 2011. Further muddling those numbers, it also includes Move and Navigation controllers.
By contrast, Microsoft reported in January that it had managed to ship over 8 million Kinect systems to retail. We don't know what their current "shipped" numbers are at the time of this writing.
You can read the IGN report, where this story finds its origins, here.