Screwed by the Lawyers: Ironically, this saved Dick Grayson from being Killed Off for Real. Editorial originally pushed for Nightwing to serve as the Sacrificial Lion during this event but a combination of Geoff Johns lobbying for Dick to live and DC (at the time) losing the Superboy trademark to the Siegel family led to Conner Kent biting the bullet instead.
Spared by the Cut: Dick Grayson was originally supposed to die during the event, with Jason Todd taking over as Nightwing. Ironically, the reason he survived is the same reason his death was considered in the first place - Dick Grayson is arguably The Heart of the DCU and his death would send shockwaves through the entire company.
What Could Have Been: The shocking villain at the end of Countdown To Infinite Crisis was originally intended to be Silver Age Teen Titans ally Loren Jupiter, likely as revenge for his daughter Lilith Clay's death during Teen Titans/Young Justice: Graduation Day but Dan DiDio nixed it as he felt that his name, Mr. J, was lame and that nobody would know who he was. Combined with the first entry it's led to speculation that Nightwing was originally intended for Blue Beetle's spot in that story.