It sounds like these old CRT iMacs are going to be long forgotten in the next decade, or so, since no one seems to be motivated enough to replace any of the major failing components (hard drives, and RAM upgrades aside). I guess this will be a significant upside for those that own a "pristine" condition iMac, as the value of their unit is surely going to increase.
The plastics on my Graphite are ok, although there has been some cracking on the white strip (which is located inside the unit) due to heat. I documented this on a thread back in October, so all of the details/pics are posted there.
I wonder if the eMacs are easier to work on. They surely look, and feel more durable than their G3 predecessors.