Aye. I've been reading on a long line of Sony Readers since 2005, and currently use a PRS-350 that I'm preserving as long as I can (I never liked Kindles). It's only a replacement for a stack of novels or other such books I intend to read cover to cover, probably once and once only. I've read over a thousand books on it, got a couple of dozen stacked up in there at any one time ready to go.
My paper book library has increased every year; novels I want to own on paper (sometimes more than one copy), books received as gifts, technical books, art books, picture books, language books, reference books, mathematical text books, graphic novels (and indeed, some things that clearly are "comics"), a significant number of books that simply aren't available in electronic form (and I probably wouldn't want in electronic form anyway - if I'm buying a book from the 1800s I want the physical artifact!), more and more.
At the moment, the only benefit I see to the Sony Reader is that it's very lightweight and compact for a stack of 12 novels. That is a very serious benefit and it's a real lifesaver for travelling, but inside the house I'm paper all the way. The only problem I have with them is that I'm genuinely running out of space to put them. Every bookshelf is two (or even three deep) with books, and I've lost one desk entirely to books piled three to four feet deep. There is a real chance that I might end up finally giving up on renting purely to buy a house in which I can turn a couple of rooms into decent book storage.