The very first time I saw an eBook display with "e-ink" a couple years ago, it was in some sort of show-room and I asked if they had one that was working, as the one in front of me had one of those plastic overlays on it which showed what it would be like if it was turned on. The woman smiled at me and said the one in front of me was turned on already. The perfectly clear, high-resolution text I was looking at wasn't printed on a plastic sheet, but was the actual display! Since then I've been a believer in e-ink... here's a high resolution picture of Sony's latest reader so you can see it yourself. It looks even better in person.
And as someone who's read two books lately on his Nokia N800 using FBReader, I'm also a big believer in eBooks in general. It's more comfortable and convenient than a paperback, and the N800 in particular has a screen with a great resolution for reading, as it's big enough to put a lot of words on the screen (equivalent to a paperback novel) and still anti-alias them, which is nice. That said, e-ink would be even better, as the clarity is so astounding. I'm sure if I tried to read for a couple hours straight using the N800, my eyes would start to get tired.
The big problem though? Contrast. I made an image above which shows what I'm talking about. Dark grey on light grey just doesn't cut it. Consumers are not going to switch en-masse to eBooks until it looks *just like* a regular piece of paper. If it's not technically possible for e-ink to do this, then readers won't switch. To me it's a no brainer...
The big news today is Amazon's foray into the eBook business, which I think is great in general if they don't screw it up with DRM and onerous syncing requirements (like Windows only apps or something), but I honestly think it's too early to be pushing it with the reader they're using. The display technology just isn't ready yet, IMHO, and will be rejected by pretty much everyone except those most enthusiastic eBook geeks until it is. Until you have honest-to-goodness black on white displays, it doesn't matter how much it costs, or how much content is available, people just won't switch until that happens.
Just my thoughts.