I think there will always be room for e-ink. This afternoon, I took an hour off to sit on the balcony and read a bit. It was so bright outside that I was barely able to read anything on the iPad. Switched to the Kindle, worked perfectly well.
I think it's a technology that fills a niche that LCDs or OLEDs won't fill for a very long time, if ever.
I don't think so. Tablets are for people that want to get the most possibilities out of their $300. e-ink readers are for people with $300 that want to read books with the least eyestrain. I read on my phone and it just doesn't feel like reading. When I use my Kindle, it does.
(I think the problem is actually with page turns rather than the pixels; turning pages on the Kindle Android app is very flaky. On the physical hardware, it works much better.)
EDIT: Something more recent - http://www.youtube.com/watch?v=ag4HGceyVik . The colours seem to be lacking contrast but I'm sure that'll be improved as better filters are developed.
Mirasol and the like seem to be providing quite a good compromise - http://www.the-digital-reader.com/2012/01/01/review-kyobo-mi... That particular reader has the problem of not being as polished as the Kindle but it seems that the screen is rising up to the expectations.
It would be cool to have the e-ink Kindle on that comparison there, too:
http://www.e-ink-info.com/ipad-slcd-vs-kindle-e-ink-close