Odd thought - Xena and Gabrielle have 20th century reincarnations; If I remember the timing right they'll be fairly elderly ladies when Superman makes his debut, but that doesn't necessarily rule out some renewed contact after L&C return to the 20th century.
If we get to meet Hercules too, it's worth remembering that in Hercules / Xena canon he's (a) an immortal demigod and (b) around in the 20th/21st century using the identity of actor Kevin Sorbo.
