I pre-ordered two of the Player's Handbooks for the public library I run - one to go in one of the prize packages for this year's Summer Reading Club, and one to go in our circulating collection. I have also pre-ordered one each of the DMG and Monster Manual for the circulating collection. We already have all the main Pathfinder books, the Edge of the Empire books, and a few other core rulebooks (like Savage Worlds) in the collection for patrons to check out.
I won't order a copy of any of the D&D 5e books for myself until I have had a chance to look through them and see if they interest me.