Anchorhead said:

Fortunately, Lucas sold the franchise before he could explain Ben's name. You know, because Lucas is so clever with regard to names e.g., Sidious, Tyranus, Grievous.

Left to Lucas we may have eventually learned Ben's real name was Count Infectious, or Lord Contagious, or maybe Senator Atrocious.

I'm sure Lucasites will claim that the Dark Lord's moniker was meant to evoke the image of a Dark Father but we know the code was originally going to be words beginning with "in" but with the "in" taken out ergo Sidious but then he thought Darth Capacity and Darth Absentia sounded a bit fem.

So Maul.

I can just imagine Christopher Lee talking to his agent, "So his birth name is Duke Dooku?? What's his Sith Moniker Darth Diplodocus? *giggle* WHAT! You better be 5h1tt1ng me!"