Villains have always been a problem; Ares, Circe, Cheetah, and Psycho are all great when used properly (although Psycho is in some respects not a really good fit for the types of stories Diana usually is in) (of the JLA Big Seven, only Aquaman and the Martian Manhunter are worse off than her (2 and 0 great rogues, respectively), and they generally can't support series at all as a result).
For all Heinberg's runs flaws (which were legion), he actually did scrape up a fairly decent group of "Who?"s from past comics; from the brief descriptions, there's new stuff to work with there (not that Heinberg actually did, since he's just dropping by for five issues rather than actually devoting significant time to re/building her rogues gallery, so he just threw in a bunch of names to show off their powers once).
On the subject of the upcoming WW DVD from Timm and co., I have a lot of apprehension about that; whatever good moments JLU Diana had, she was an abysmal translation of the comics Diana, and basically every time they employed elements of her comics they fell flat on their faces (excepting Circe; she was hilarious, although I know a lot of WW fans don't like that her archenemy was made into a joke). Even in the JL: New Frontier movie they threw in that utterly bizarre non sequitor where the other Amazon tries to kill Diana.