In general, some of the dungeon complexes released with the launch of World of Warcraft took labyrinthine to new extremes. As much as I love it, Blackrock Depths is a positive pain to navigate for a new party - it was terrible before the dungeon finder existed, it's not any better now. Modern dungeons tend to have moved as far away from the 'sprawling mega complex' design as possible. Current dungeons tend to be what I call 'bite sized' in comparison - smaller, self contained wings or experiences that contain between three and four bosses, to be consumed in a 20 to 30 minute chunk of time with four strangers via LFD. It's understandable and even unavoidable that this had happened, but I think there's some wisdom in considering how to have a happy medium between these extremes.
Dungeons like Dire Maul, for instance, saw minimal change in Cataclysm because it was already perfect for the new system. Three wings, mostly self contained (one could previously get from north to west via a tunnel into the library, which was removed) with a reasonable assortment of bosses, tied together by theme yet distinct in terms of what you faced in each. Maraudon, on the other hand, is still a sprawling, difficult to navigate dungeon made worse by the addition of incredibly arbitrary starting locations that the dungeon finder only exacerbates.