Good lord, I have no idea how many 3.x D&D books I have. When it first came out until about 2005, I bought a ton of stuff for it- probably close to 500-700 books. When I moved 2.5 years ago for my new job, I packed them all up in boxes, and they are still there in my basement. My group moved away from D&D and D20 in favor of Savage Worlds and WHFRP2 (and recently some Rolemaster Classic- I didn't realize how much I missed that game), so I haven't bothered to reference or look at them in a long time. D20 and D&D 3.x just didn't mesh with our playing styles, and after a long time or trying to make it do so, we gave up.
However, what I have heard about 4E sounds great- definitely changes for the better IMO. I love the points of light concept, less reliance on magic items, and I'm looking forward to the streamlined and simplifield rules system. If 4E is as easy to prep as SW and WHFRP2 and fits with our playing style, I'll happily switch and never look back at D&D 3.x.