Most corpses don't tell you much. Occasionally they'll tell you where something valuable is. Often they're just an alternative route to get information you could get otherwise, but that's true for almost everything in the game. They've built in a ton of options. Occasionally they'll point you to where some magical gear is that you'd otherwise almost certainly miss, which can be nice. Usually it's just a source of advancing quests and getting more information on who someone was.