3. Don't Spin-Off Unnecessarily
The temptation for DC must surely be to stick with what has worked, and to look at models for diversifying key properties without going too far off brand. The ready-made solution would be to focus on Batman's allies, and to spin-off from the Batcave, focusing on Robin, Nightwing, Batgirl or Huntress, but to do so would be to fundamentally under-estimate the need for Batman to be central to all of those stories. Each of the characters - particularly Nightwing - is enduring in their own right, but they are never more appealing than when their stories converge with a Batman narrative, or when they play supporting roles in a Bats-led arc. If DC run before they can walk with these lesser characters (and they actually rank below the so-called "lesser" members of the JLA,) they will reap failure as their reward. Great characters they might be, but they can only be considered supplementary, especially at this stage when DC are struggling to find their audience, and a grander creative statement is required. Hopefully, the studio will have noted the failure of Supergirl in the past, but judging by Hollywood's tendency to repeat mistakes, you do have to wonder.