Here are some of the villains making an appearance in the upcoming Green Arrow movie written by David Goyer (Batman Begins/Batman Dark Knight/Blade (1,2,3)/Zig Zag).
Cameron Mahkent. AKA: Icicle (JSA/Alan Scott Green Lantern). Think if Iceman from X-men had a pair.
Lex Luthor (Super Man)
Edward Nigma. AKA The Riddler (Batman)
Much like Hawkeye from the Marvel Universe, Green Arrow is a bowman of some fame. However this doesn't stop him from sucking completely. I think its a very good idea to get him out of his costume and into jail stripes as soon as possible will make this an interesting movie, not to mention Goyer's involvement. I like that they are going cross-title with the bad guys because, really Green Arrow has no notable villains worth mentioning. Better to pilfer from better heroes.