Digitimes is reporting that E-Ink is now sampling colour and capacitative touch-screen electronic paper displays (EPD) to its partners. It suggests that models may start rolling out by the end of 2010 or early 2011. Manufacturer Hanvon, which makes the WISEreader, is mentioned as planning to roll out a colour model in Q4.
In my opinion, colour is crucial to the success of the e-book market, much more so than touch or video capabilities, as it makes buying illustrated non-fiction and reference books in digital form more attractive. Current readers only have greyscale capabilities. It remains to be seen what, if any, effects the addition of colour will have on battery life.