@CptBedlam: How dare they use something from ancient Greek mythology to name a character design. No game would ever do that!
Dude, I know were the name originates from but this is a "the latest thing" issue. Why would you pile on with that after other games (and movies) already exhausted the concept lately? Come up with something better, turn to other mythologies. It's not that hard to find interesting inspirations but they went the laziest route (Protoss, Protheans, Prometheans...).
Why would you come up with yet another ancient alien race that looks like glowing robotic insects and even name it similarly? All this shit starts to look and sound the same.
How is it a latest thing? Naming characters/concepts/ships after mirroring Greek mythological figures is pretty much a trope in literature as old as Greece itself. Your argument is like saying because a bunch of movies share the first letter of their names they are all derivative of each other. Obviously they were named Prometheans because something in their back story will mirror the Greek tale. That's all.
Hey, let's hope this isn't a spoiler but I bet it turns out the Prometheans are not monsters but really wise and honorable guys.
Prometheus is (essentially) greek for "Forethinker" and is the trickster Titan who is credited to making man and is subsequently condemned and tortured eternally for this. It's not hard to see where they will fall in place in the Halo mythology.