Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
The only way to have a "completely thin" display panel is to do what Microsoft has done with the Surface Studio -- move the logic board, power supply and connections down to a "box in the base".

Granted, the Surface Studio base looks different and slightly "bulky" compared to the existing iMac base, but all that stuff has to go someplace.

And down in the base, it would be easier to access (if necessary), as well.
 
water cool an iMac? Are you serious?

Even some diehard gaming enthusiasts don't touch the stuff. People want to use a computer, not have a "watercooling computer guy", like a plumber...those guys are real cheap and will come to your house on a Sunday to fix your stuff. Not.

Using a water cooled AIO PC to watch cat videos and send a few emojis is a TERRIFIC idea. o_O
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.