Despite everyone already knowing Pronger's career was over, the team has never openly acknowledged that fact previously. There have been insinuations about Pronger looking to get healthy and the like, but never a definitive statement regarding his future.
His brother, Sean Pronger, stated in a Deadspin question-and-answer session in January of 2013 that he thought Chris would never play again but expressed that he couldn't speak about that definitively. Previous accounts have indicated that Philadelphia couldn't acknowledge the end of Pronger's career because of salary cap issues that would come with his retirement.
As we all know, the Bruins are dealing with a similar issue with Marc Savard. As most recall Savard suffered two concussions in a matter of a year and has yet to touch the ice in over two years. At 36 years old, Savard could have still been contributing to the Bruins for the next couple years, but it looks like he will have the same fate as Pronger.
Pronger on the other hands is one of the best defensemen to play the game. He was a huge acquisition for the Flyers 4 years ago, and it is a shame he will never get to skate again.
This brings a question about player safety in the NHL. As we all know the league has been cracking down on hits and even has gone as far as altering the rules for fighting, yet we always see the story of a player getting a serious injury. Hopefully the NHL does not become hitless, but much more safer, so that players can play longer.