Dead in the sense that support has dropped, of course. Originally launched in 1998, the iMac was certainly a unique looking computer, which also happened to popularize USB ports. At that time, USB seemed incredibly impressive. September 18th is the day of doom, where support is dropped.. no parts will be available for purchase from Apple directly. This doesn’t mean that third-party vendors won’t have them, but chances are prices will go up, and parts will be harder to come by.
Come September 18 we’ll all be wearing black, mourning the death (or celebrating the life) of the slot loading iMac. Yes, the computer that brought USB to the masses and brought the Mac OS back into our hearts gets end of life’d on that fateful Tuesday. Once the 18th hits, Apple will no longer offer service parts or documentation to repair centers for this model iMac.
Source: CrunchGear