Valve's award-winning Team Fortress, Portal and Portal 2 writer, Erik Wolpaw, has discussed the changes in the relationship between Chell and GLaDOS in Portal 2.
In an interview with Gamasutra, the man who put the words into GLaDOS' voice box discussed the way in which GLaDOS now perceives Chell, given the events of the first game.
"Certainly, the relationship has changed since Portal," said Wolpaw. "She does know that you're dangerous. There's certain stuff it would be spoilerish to talk about, but yeah, your relationship has changed."
Wolpaw emphasised that Portal 2 will continue to focus on the relationship between GLaDOS and Chell, even amongst the introduction of numerous new characters and gameplay mechanics.
"...despite being a game it told this intimate story about your relationship with this one other character. Even though we want to introduce a few new characters, we want to keep the core piece of the story as your relationship with GLaDOS, and how that's changed by what you did in Portal, and then have some place to go as the events of Portal 2 unfold." revealed Wolpaw.
One of the newly announced characters is Wheatley, a personality sphere voiced by UK comedian Stephen Merchant.