We've done a couple time jumps, but nothing to cause people to retire...
Out of the original four characters, both sets produced offspring, one of which became evil, the other grew to be a mighty Fighter. SHE eventually had a child as well, but this one was magically aged for a plot of mine, and ended up becoming a demoness... She hasn't appeared yet in 3E.
The original characters became Immortals (the last adventures of Basic D&D before time jumping to 2E), but have since been thrust back into mortal bodies. They live in the past though, and it's kinda funny. "What class are you guys, anyway?" "I am a Fighter! And my friend here is an Elf!" They haven't appeared yet in 3E though...
I plan on doing periodic time jumps in the future, though...
Chris