After you rescue Covetous Shen from the water way in Act 2, he's pretty chatty. He talks about the architecture at one point stating, "You could walk all the way around the world and never see its like."
Immediately following, he says something very curious, "Except for this part. I've seen this somewhere before."
How intriguing. Is Covetous Shen hinting at something in particular? Could it be a nod at a previous Diablo game? Basically, should the player have any idea what he's talking about?