The Caverns of Time was a gloriously refreshing change from that, and I'm glad they took something out of that poll they did awhile back. The previews of The Occulus and Caverns of Time: Stratholme were fantastic, and that nonlinearity is one of the best parts, easily. Even though you will probably have killed all of the same bosses in the end that you would have if the dungeon were linear, just in a different order, having choices available and environments that aren't simply enclosed hallways that go in one direction really brings a place to life. It's hard to believe that the Botanica is just one really long constant hallway, for example.
Here's hoping that these elements extend beyond Old Stratholme and The Occulus, and Wrath will bring dungeons back to life.