I jumped off a ledge in a dwarven ruin and my follower, he's a warrior cat from dawnstar, Kha... He was left quite high up above me and couldn't find a way down. And normally he, and others, will leave me and find a way of walking down, but he jumped down to me, not walked off, but took a jump down to me. I was beginning to think npcs could not jump, or would not, because I've never seen it. And I think it is kind of frustrating, but I got a big kick out of seeing him jump down to me finally.
Before I knew about the 'hit the wait and hr and the follower will by your side' thing, I had a follower that wouldn't jump. It was very annoying. I actually went through the all the way through the cave, then came around to get him and "Fus'd" his ass off the ledge (I needed him to carry some stuff). I've notice now too that they jump down with you more. May have been in one of the patches that was released.