Here is video playing on the new eink panel used in the Paperwhite (running in a Freescale i.MX50 EVK Development kit):
They are only doing about 5 FPS, like the video player that was running on the Nook Simple Touch. My gmplay "overclocks" the eink up to 7.7 FPS (limited by the K3). I can go a lot faster on the K4/K5, but no need...