It's unlikely Amazon will release another large - screen E Ink ereader again, especially now that they've invested in color electrowetting display technology. (blog.the-ebook-reader.com)
LiquaVista displays use electrowetting technology to produce full color displays that -LSB-...] (liliputing.com)
Electrofluidic displays are a variant of electrowetting displays - which do require power to hold an image. (e-ink-info.com)