User blog comment:ScarletWhisper/No Red Hood In Season 2/@comment-5154078-20121001041816

It would be wise to take into account the ages of the characters. We know from Issue 20 of the tie-in comic book that Nightwing is currently nineteen years old as of the most recent episode of the series. According to the producers, Tim Drake, the Team's current resident Boy Wonder is fourteen. Assuming that Jason Todd died and even could have possibly been resurrected by this point (unknown to either the Team or the Justice League), his most likely age would have to be somewhere between sixteen and seventeen. So, an appearance by Jason Todd as Red Hood in the second season does not appear to be likely. The whole purpose of Red Hood as a powerful Batman villain loses something in the lack of physical and mental maturity.

If "Young Justice" does make it to Season 3, he would definitely be on my list of most wanted antagonists. But for Season 2, you can only fit so much into twenty episodes.