Last night I was running along a road in Bangkorai when I saw a troll on the road heading toward me. I instinctively backed up, surprised by the sight of a troll walking on a road, apparently on the way to somewhere. I'd never seen any NPC follow a road before.
I followed him from a distance. He stopped near some rocks and was doing...something...then he turned around and headed back the way he came. I followed him again, to a bridge, where he stopped for a bit, then repeated his "route". His patrol range was pretty large.
Since I've never seen any NPC do this, I assume he's part of some quest I haven't picked up yet. But it was kind of neat, and it occurred to me that you don't see NPC's in ESO ever go very far from their "anchor" spot. I think it would be cool if more NPC's - especially formidable ones like trolls, or maybe groups of 2 or 3 regular mobs, wandered around a bit. They don't need to be all over the place, but running into them here and there would be fun. I thought running into that troll added an interesting dynamic to the game.