According to Robert Arrowood, Tyler Hodgson, and Micheal Astor, 1G Talons and Lasers have the fog light wiring installed, even if they did not come with the actual lights. They also give a list of components that must be added to enable the harness to work properly. Since another user reported the same was true for his 1994 Talon DL, this may be true for all 1G Talons.
Unfortunately, Micheal reports that Eclipse cars may not have the harness. This is only the impression of an anonymous Mitsubishi technician, however, and may or may not be true.
2G owners might also be out of luck as both Patric Sansoucy and David Parker both had to run new wiring when installing fog lights on their cars.
The Last Word: Brian Chapman states definitively that the 1990-1994 Eclipse cars do have the fog light wiring harness installed, even when the fog lights themselves were not installed. [Thanks, Brian!]