I know nothing about what they have achieved in the execution of the whole thing, but the most exciting concept that I've seen for 2008 Vacation Bible School is Group's Rome curriculum, subtitled "Paul and the Underground Church." I find it exhilarating to look at a curriculum for Vacation Bible School and see clearly that it might have something to do with the Bible.
BTW: Our first loyalty is to Lifeway. If all the VBS choices are equally uninspiring, we generally purchase Lifeway's curriculum for the year. But if somebody's curriculum offering stands out (Lifeway's or anybody else's), then we are willing to go with that.