The Walking Dead - Episode 2.11 - Judge, Jury, Executioner - Interview with Robert Kirkman

So, it’s rest In peace, Dale.
ROBERT KIRKMAN: Indeed.

Would you care to say a few words about the dearly departed?
I think it’s a monumental death for the series. Dale’s character has been the heart and soul of the show. He’s definitely the moral compass. He’s the guy that, more so than anyone, has been warning people to be careful how you let this world change you and monitoring what lengths people are going to survive. His loss is going to mean a great deal for all the characters in the show and is definitely going to represent a turn to a darker space. His death means a lot.
It’s heartbreaking to lose Jeffrey DeMunn. He’s really given us a lot, these last two seasons on the show. It’s been amazing to work with him and get to know him and he’s an awesome dude and we’re definitely going to miss him.

Why did you decide to pull the trigger on Dale?
It’s really just about how it affects the other characters. That’s the main thing that goes into a decision to kill a character: “What does this get us?” Having an amazing ending to the episode and really showing the viewer that this is a dangerous world and anyone can go at any minute and getting the shock value of that is great. But, at the end of the day, it’s “How does this affect things six episodes down the road? How does this affect things ten episodes down the road?” That’s really the question. Once we started working that out in the writing room and seeing how Dale’s death affects Shane and Dale’s death affects Rick and Daryl and Lori and Andrea and all the way down the list — that’s really what helped us along in this decision.

Source: Full interview @ Entertainment Weekly