In praise of...
I have a Sony reader, and I am getting a LOT more reading done than when I read on paper.
I don't have time to get to bookstores much, but I can get an eBook online in 30 seconds. Also, I've got currently about 300 books in my reader (4GB card) - I don't have a real plan for what to read next, I just keep a few dozen things on there and pick one when I finish the last book. It's nice to be able to pick any book out of the library while waiting for an appointment or at lunch.
As for "useless when the power is out" - a charge on the Sony reader will last 7500 page turns, which is about 10 good-sized novels (there's not quite as many words to a page on the Sony). It's true, if you can't get near any kind of power for the time it takes you to read 10 full novels, you'll run out of power. This isn't a huge problem for me, maybe others live in the woods or often have power outages that last a week or two (or perhaps they read more than 2 or 3 novels a day). Personally I take mine on 2 week vacations and don't bother to pack a charger.
I find it much more comfortable to curl up with the Sony reader than with a paperback. I don't have to hold the thing open, and I don't have to shift around every other page to read the left, then the right page, when I'm lying down.
BTW, count me as a huge fan of Baen books. I give them as much money for ebooks as I can, for they're about the only company that "gets it" - non DRM books (which I respect and DO NOT share) for cheaper than paperbacks, usually $4 or so, and I bet if any extra is made from the eBook, Baen passes a chunk of it to the author, because they're an ethical company.
@Matt - NO common book being printed today will last more than perhaps a hundred years or so. Even after 50 years, paperbacks are looking pretty ratty; the cheap paper just falls apart.