[EDIT] to be clear, I'd love for e-readers to actually achieve enough of the important features of physical books that I could mostly switch over. I'd probably hold on to a few real books but I'd happily ditch 90+% of them if they weren't a better interface for their particular content, in ways that really do matter, than ebooks. Color, higher resolution, and probably at least two screens per device (or one foldable screen I guess) would be required to even take a realistic stab at that, though.
Then again there's no way I'd pay new-ebook (only kind) prices for all the books I have. I could slowly start converting, though, if they were good enough. It's a features thing, not (entirely) a nostalgia thing.