Majorly from Matt Fowler/Eric Goldman at IGN, & folks who attended the event
  
"If they'd given us a full order we might have tried to tap dance  with another season and we'd have gotten called out on that" - Nolan
  
Nolan wished they could have brought back Paige Turco & Camryn Manheim back, but the scheduling didn't work out.
  
"When Elias hit in Season 1 I think people realized that the show would be more than just case-of-the-week." - Plageman
  
Root died in the car. The ambiguity gave a false sense of hope. "Sometimes superheroes die alone in the dark" - Nolan
  
"The idea was always to end as an ensemble," - Nolan, talking about how the show started as a two-hander
  
"The whole thing's gonna turn on a fit bit." Greg Plageman, on the finale
  
Nolan & Plageman had an end song in mind for the show, but then the POI composer made a piece of music that was perfect. 
  
Plageman could possibly see #PersonOfInterest return in some way,  though fans may think differently after the "bloodbath of the finale."
  
"I think you'll be happy with the finale."-Greg Plageman "Or, really unhappy."-Jonah Nolan