I've ended up donating a couple thousand books over the last three years due to space limitations. I just thank all of the e-reader gods that the last years cull was all books that I had electronically, and not ones I was betting I wouldn't want to re-read again.
I'm definitely a "re-reader". My favorite paperbacks will get read dozens of times, until there's little left. (And I'm nice to books!)
But I imagine most of my paperbacks will go away over the next year or two. Now when the plasticlogic beastie comes out, and my tech books can start going, that'll be a happy day!