I believe some companies are claiming 20ms refresh rates, which is hitting 50fps if these claims count for continuous changes or just one-offs. Certainly a lot of display manufacturers have been showing off video, but you've got to consider the growth rates here can be biased for one reason: colour.

E-ink and every other company wanting to produce e-paper want colour. If they can hit continuous frames above 24fps in full colour, then they've got a massive game changer. I mean think of the game change in laptops where the display uses 60-70% of the battery life of the device if you're capable of dropping that to 5-10%. Your average piece of shit netbook will run 24-hours. Your laptops that already run through a full business day plus commute, will be able to last you the full week and maybe a saturday on a single charge.

I think the black&white e-ink displays aren't advancing as fast as they could be simply because developers are trying to find their holy-grail of a video-capable colour display.