Matches Malone was a small time crook who was actually a decent human being. Batman, learning of Malone's nature, approached him for help tracking Ra's al Ghul. But Matches wanted no part of it, and while attempting to shoot Batman, accidentally killed himself with a ricochet. Not wanting Malone's death to be a total waste, Batman donned a fake mustache, plaid suit, and goofy Jersey accent and began impersonating Matches to infiltrate Gotham's gangs.
He's used this identity many times over the years, most notably in the War Games storyline. Batman had developed a plan in an emergency to take over Gotham's underworld by uniting the crime families under Matches. Stephanie Brown, the 4th Robin, was desperate to make a good impression on Batman, found the plan and set it in motion without telling Batman. But when Matches Malone failed to show, it ignited a massive gang war that nearly destroyed Gotham.
Pros: Matches Malone's organized crime career makes him a good fit.
Cons: Giving him any kind of backstory is probably pointless, since as an alias of Batman, he's not really a villain.
How I'd do it: Probably just come up with an excuse for Batman to go undercover.
Casting Guesses: Christian Bale.
Verdict: Not out of the question, but he won't be a major player. But if Batman does have to go undercover, it would be a nice touch to use the Matches Malone alias. But without the plaid suit.
After The Scarecrow, Ra's Al Ghul, The Joker, and Two-Face, who should be Batman's next enemy in the Batman Begins/The Dark Knight series? Well, as of now we know that Tom Hardy will play Bane and Anne Hathaway will play Catwoman.
Check out the master list for all the villains covered. I've pretty much run out by now. Obviously, there are more Batman villains, but not any of significance that I know of. As of February 2009, no one is confirmed as a villain. Not the Johnny Depp Riddler, not Phillip Seymour Hoffman Penguin, nobody.