As some have already noted, it is appropriate to separate ebooks from ereaders. ebooks will continue (assuming no apocalyptic events forcing everyone back to paper), but I think the days of the dedicated ereader are numbered. Probably not soon, but I expect ereaders to become collectors curiosities well before paper books get there. With my future-seeing-goggles on, I think paper books will remain common for at least another generation, while dedicated ereaders will be lucky to see out another 10 years.
Then again, since I got the goggles cheap from a man that also offered to sell me the Sydney Harbour Bridge for dollar, there's a chance I could be wrong. 