At the time there was no endgame, so when I got my first hero to 50 I went, "Meh, new character."
After the VEATS debuted I decided to take a serious stab at leveling a villain...an elec / elec brute who was pretty goldurned fun to play. When I got him to 50 I went, "Yahoo! New character!" and rolled my first widow. Oh, widows, how I miss ya.
Finally, when the incarnate stuff hit, I blew the dust off of my collection of 50's and started playing them again. Endgame, at last!