I believe that netbooks COULD kill off ereaders when the eink tech is one option on the netbook, they are in the pipeline, and should be coming out within year or so. So you can then switch it to eink or lcd regular mode, and get good battery life in eink mode. and when they can have swivel screen, when in eink mode screen on top, then swivel screen and open and switch to regular computer lcd backlight mode for movie mode.
At this point I do have netbook and prs-505 and I like the 505 because it's small, can put in my pocket, start-up time is 1/2 second.
Last night in town, outside of nightclub , they had bench with street lamp right behind it, opened the 505 and set it to Biggest font size and had no trouble reading. I was surprised I can read this at night as long as street lights are around.