Fanservice special? The hell? She's already walking around nude most of the time as it is. It's certainly a lot more skin shown then a lot of other series that have wussed out recently (inb4 TV vs DVD comparison images). Hell, even the 'naughty' and fog-less DVD editions don't compare to Horo's bare ass.
There's really nothing left they can show, at least not anything short of full-blown hentai, and I highly doubt that'll happen outside of the doujins.
So what could they possibly be saving... Oh God... It's not going to be LAWRENCE's bare ass all over the screen is it?