Well, someone in my mother's "blackmail stash" is a picture of me at the age of 8 going to bed with four, count 'em four, of my favorite books!
My lifelong love affair with books includes the physical object as well as the content! So no, my ebooks won't replace my library any time soon.
I do, however, think it will make me much more
selective about which books I buy and in which media. If I really, really love a book to the point of obsession, I often buy more than one copy: one really good collectible/first edition (the best I can afford), which gets a place of honor on my shelf and is lovingly cared for; and one "reading copy" which can be tossed into a bag and otherwise molested.
However, if I know that I probably won't read it more than once or twice - like most of the trade paperbacks - I think now I would buy it as an ebook. Those tend to get donated to the library eventually anyway.
And actually, now that I think about it, the "reading copy" referred to above could be the ebook as well! So while ebooks won't
replace my library, I think they will definitely have an impact on its size!