It seems to me that few people really like to weed. I'm not sure I particularly love it, but there is something very satisfactory about clearing the collection of unwanted and unused items. I don't think academic librarians will ever hear the end of comments about how all the books in the stacks are old, but at least we can do our part to weed out some of them.
Right now, we are rather short on shelf space on the third floor of our library. While another row of shelving might be nice, I suspect we can clear a decent amount of space just by doing a bit of weeding. We are focusing first on duplicates (ever-so-affectionately called "dupes"). For the most part, academic libraries do not need duplicate copies of items, especially if they are rarely, or never, used. We are starting with the particularly tight areas, and will then move on to the rest of the third floor.
Then, we'll weed, starting with the tight areas, and finally we'll shift the whole floor.
The project will take a while, but I think we'll see a nice benefit of all the work. I am nearly finished shifting all of the books on our second floor. I've been at it for maybe 2 years, because I can only shift during breaks - the second floor is our only quiet study floor. It's really nice to see all the shelf-space now available in previously constricted areas. I'm sure our student workers appreciate the ease of shelving. Whether anyone else notices, who knows.
And, of course, all our weeded books go to Better World Books. I love their library discards program and highly recommend it.