Anyone who plays videos games knows pre-order bonuses for those willing to pay in advance of product launch. WotC's official toolset, D&D Beyond, is adopting this practice with 16 bonus feats exclusive to those who pre-order Xanathar's Guide to Everything on D&D Beyond.
Songwriter Mary Crowell's music has featured here on EN World before, and this is an old favourite updated with a fun video! "I wrote a song back in 2009 about my favorite D&D spell and put it on my album Acolytes of the Machine. Abut a year ago, I started making a variety of silly music videos with the help of local gamer friends and online and convention friends who sent me clips of them and their friends as wizards or zombies or villains (depending on the video.) At long last, I got to make M is for Magic Missile. Enjoy!"