You are not the only quilter who decorates cakes, you know! Diane, whose blog Diane's Decorating Diary is in my sidebar, is also an expert cake decorator. It's a hobby that has almost as many supplies as quilting, though, so beware! :D
I'm definitely almost as addicted to cake decorating as I am with quilting :) , and you're so right! I've accumulated alot of supplies over the past year from all the courses I've taken! So fun though!