I just got my Nook like, 3 days ago, so i haven't technically bought a pbook since, BUT i did buy Stardust a week ago.
But I've already had a plan in my head for when I did finally move to digital- It goes back to Beauty and the Beast and that scene where Beast gives her that enormous Library as a gift? That scene has been with me ever since I was a kid and I always knew that my house would have some kind of library, even if it only is one ikea like shelf. SO basically from now on I'm shopping purely digital, Unless I read an utterly fantastic book , THEN that one gets purchased in physical format too and added to my library so that I have a bookcase full of only the "good stuf"