Surprisingly absolutely nobody. The only thing I got wrong was him being a counter for Nightwing. They've set him up as Green Arrow's opposite, due to the television series. Still. 2 for 2.
Along with the confirmed via box art Green Lantern and Joker, technically 3 for 4. Here's hoping the next character is someone no one is expecting, but everyone likes. But more likely, it's just Green Lantern.