November 1st is the last day of Hallow's End, so come next Thursday, not only will you be sick from all the candy, but the costumes, decorations, and yes, the brooms will all be gone. Get that magic broom flying in now while you can, because in just a week, they'll be takin' yo' broom.
Update: A few players are saying that the brooms will disappear after 14 days of /played time, not after November 1st. My understanding was that when Hallow's End is over, so is the broom riding. We'll find out next Thursday. Happy Halloween!