When I wrote my post about E Ink persistency, I noted that E Ink has a display at their office that was turned off in 2001 - and it still shows the image correctly. A nice reader just sent me the following photo, showing an Active-Matrix E Ink display that was last refreshed on November 2000 - yes, 11 years ago!
This panel was developed by Philips, with the front panel made by E Ink and the back plane (AM) made in Philip' LCD plant in Kobe, Japan. The reader says that this is actually the world's first active-matrix E Ink panel, and is probably the oldest one that still shows an image. Over the years it has long some of its contrast, but the image is still clearly visible.