I'm kind of a magpie, and kind of a turtle. I don't pick up on every shiny new fandom that comes along, but I do pick up on new fandoms probably every year or two, usually around the time that large numbers of my favorite writers move on to them. I mostly keep my old fandoms around, but I pay a lot less attention to them than I do the current fandom. I'm hardly ever really excited about more than one fandom at a time.