I'm very much unconvinced that the idea of Dark Elves as a distinct race/species is worth saving. Having evil elves as a distinct species from "normal" elves (let alone one distinguishable by skin color) was a horrible choice from the beginning, but as far as I can tell, it's the central reason for having Dark Elves, and any future iteration is going to be perceived in relation to that history. So while the Dark Elf concept certainly can be improved from its historic origins (indeed it would be hard not to improve), I think abandoning this concept and focusing on novel cultures and species would probably be a better use of creative energy.