In a forum post today, Bashiok replied to a player who was unhappy with the health bars and name tags appearing over the heads of every monster. The fan thinks they’re distracting and unnecessary. Bashiok said:
I think we essentially agree with you. The floaty ‘above creature’ health bars raised a few different concerns and they’ve since been changed. Health bars for uniques and bosses are displayed at the top, and health bars for everything else are displayed at the bottom (both stationary). It works well, it’s all out of the way but still accessible if needed and more importantly you can keep an eye on boss/unique health as well as any lesser minions you happen to be fighting.
Check out the previous form of this display on a unique monster in this image of the Siegebreaker. Compare that to the (now eliminated) view of it over a regular monster. Both images are from the WWI gameplay movie in June 2008.